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Theorem List for Metamath Proof Explorer - 30401-30500   *Has distinct variable group(s)
TypeLabelDescription
Statement
 
Theoremlvolnelpln 30401 No lattice volume is a lattice plane. (Contributed by NM, 19-Jun-2012.)
 |-  P  =  ( LPlanes `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( K  e.  HL  /\  X  e.  V ) 
 ->  -.  X  e.  P )
 
Theoremlvoln0N 30402 A lattice volume is non-zero. (Contributed by NM, 17-Jul-2012.) (New usage is discouraged.)
 |-  .0.  =  ( 0. `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  ( ( K  e.  HL  /\  X  e.  V )  ->  X  =/=  .0.  )
 
Theoremislvol2aN 30403 The predicate "is a lattice volume". (Contributed by NM, 16-Jul-2012.) (New usage is discouraged.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A ) 
 /\  ( R  e.  A  /\  S  e.  A ) )  ->  ( ( ( ( P  .\/  Q )  .\/  R )  .\/  S )  e.  V  <->  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 ) ) )
 
Theorem4atlem0a 30404 Lemma for 4at 30424. (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  ( P  e.  A  /\  Q  e.  A ) 
 /\  ( R  e.  A  /\  S  e.  A ) )  /\  ( -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 ) )  ->  -.  R  .<_  ( ( P  .\/  Q )  .\/  S )
 )
 
Theorem4atlem0ae 30405 Lemma for 4at 30424. (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( K  e.  HL  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P 
 .\/  Q ) ) ) 
 ->  -.  Q  .<_  ( P 
 .\/  R ) )
 
Theorem4atlem0be 30406 Lemma for 4at 30424. (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( K  e.  HL  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  -.  R  .<_  ( P 
 .\/  Q ) )  ->  P  =/=  R )
 
Theorem4atlem3 30407 Lemma for 4at 30424. Break inequality into 4 cases. (Contributed by NM, 8-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A ) )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 ) )  ->  (
 ( -.  P  .<_  ( ( T  .\/  U )  .\/  V )  \/ 
 -.  Q  .<_  ( ( T  .\/  U )  .\/  V ) )  \/  ( -.  R  .<_  ( ( T  .\/  U )  .\/  V )  \/ 
 -.  S  .<_  ( ( T  .\/  U )  .\/  V ) ) ) )
 
Theorem4atlem3a 30408 Lemma for 4at 30424. Break inequality into 3 cases. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) 
 /\  ( U  e.  A  /\  V  e.  A ) )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 ) )  ->  ( -.  Q  .<_  ( ( P 
 .\/  U )  .\/  V )  \/  -.  R  .<_  ( ( P  .\/  U )  .\/  V )  \/ 
 -.  S  .<_  ( ( P  .\/  U )  .\/  V ) ) )
 
Theorem4atlem3b 30409 Lemma for 4at 30424. Break inequality into 2 cases. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  V  e.  A )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P 
 .\/  Q )  /\  -.  S  .<_  ( ( P 
 .\/  Q )  .\/  R ) ) )  ->  ( -.  R  .<_  ( ( P  .\/  Q )  .\/  V )  \/  -.  S  .<_  ( ( P 
 .\/  Q )  .\/  V ) ) )
 
Theorem4atlem4a 30410 Lemma for 4at 30424. Frequently used associative law. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( P 
 .\/  ( ( Q 
 .\/  R )  .\/  S ) ) )
 
Theorem4atlem4b 30411 Lemma for 4at 30424. Frequently used associative law. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( Q 
 .\/  ( ( P 
 .\/  R )  .\/  S ) ) )
 
Theorem4atlem4c 30412 Lemma for 4at 30424. Frequently used associative law. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( R 
 .\/  ( ( P 
 .\/  Q )  .\/  S ) ) )
 
Theorem4atlem4d 30413 Lemma for 4at 30424. Frequently used associative law. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( S 
 .\/  ( ( P 
 .\/  Q )  .\/  R ) ) )
 
Theorem4atlem9 30414 Lemma for 4at 30424. Substitute  W for 
S. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  W  e.  A )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R ) )  ->  ( S  .<_  ( ( P  .\/  Q )  .\/  ( R  .\/  W ) )  <->  ( ( P 
 .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( P 
 .\/  Q )  .\/  ( R  .\/  W ) ) ) )
 
Theorem4atlem10a 30415 Lemma for 4at 30424. Substitute  V for 
R. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  V  e.  A  /\  W  e.  A )  /\  -.  R  .<_  ( ( P  .\/  Q )  .\/  W ) )  ->  ( R  .<_  ( ( P  .\/  Q )  .\/  ( V  .\/  W ) )  <->  ( ( P 
 .\/  Q )  .\/  ( R  .\/  W ) )  =  ( ( P 
 .\/  Q )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4atlem10b 30416 Lemma for 4at 30424. Substitute  V for 
R (cont.). (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  V  e.  A )  /\  ( W  e.  A  /\  -.  R  .<_  ( ( P  .\/  Q )  .\/  W )  /\  -.  S  .<_  ( ( P 
 .\/  Q )  .\/  R ) ) )  /\  ( R  .<_  ( ( P  .\/  Q )  .\/  ( V  .\/  W ) )  /\  S  .<_  ( ( P  .\/  Q )  .\/  ( V  .\/  W ) ) ) ) 
 ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( P  .\/  Q )  .\/  ( V  .\/  W ) ) )
 
Theorem4atlem10 30417 Lemma for 4at 30424. Combine both possible cases. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( ( R  e.  A  /\  S  e.  A )  /\  V  e.  A  /\  W  e.  A ) 
 /\  ( P  =/=  Q 
 /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R ) ) ) 
 ->  ( ( R  .\/  S )  .<_  ( ( P 
 .\/  Q )  .\/  ( V  .\/  W ) ) 
 ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( P  .\/  Q )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4atlem11a 30418 Lemma for 4at 30424. Substitute  U for 
Q. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )  /\  -.  Q  .<_  ( ( P  .\/  V )  .\/  W ) )  ->  ( Q  .<_  ( ( P  .\/  U )  .\/  ( V  .\/  W ) )  <->  ( ( P 
 .\/  Q )  .\/  ( V  .\/  W ) )  =  ( ( P 
 .\/  U )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4atlem11b 30419 Lemma for 4at 30424. Substitute  U for 
Q (cont.). (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) 
 /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A ) )  /\  ( ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 )  /\  -.  Q  .<_  ( ( P  .\/  V )  .\/  W ) ) 
 /\  ( Q  .<_  ( ( P  .\/  U )  .\/  ( V  .\/  W ) )  /\  R  .<_  ( ( P  .\/  U )  .\/  ( V  .\/  W ) )  /\  S  .<_  ( ( P 
 .\/  U )  .\/  ( V  .\/  W ) ) ) )  ->  (
 ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( P  .\/  U )  .\/  ( V  .\/  W ) ) )
 
Theorem4atlem11 30420 Lemma for 4at 30424. Combine all three possible cases. (Contributed by NM, 10-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A ) 
 /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A ) )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 ) )  ->  (
 ( Q  .\/  ( R  .\/  S ) ) 
 .<_  ( ( P  .\/  U )  .\/  ( V  .\/  W ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( P  .\/  U )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4atlem12a 30421 Lemma for 4at 30424. Substitute  T for 
P. (Contributed by NM, 9-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( K  e.  HL  /\  P  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )  /\  -.  P  .<_  ( ( U  .\/  V )  .\/  W ) )  ->  ( P  .<_  ( ( T  .\/  U )  .\/  ( V  .\/  W ) )  <->  ( ( P 
 .\/  U )  .\/  ( V  .\/  W ) )  =  ( ( T 
 .\/  U )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4atlem12b 30422 Lemma for 4at 30424. Substitute  T for 
P (cont.). (Contributed by NM, 11-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )
 )  /\  ( ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R )
 )  /\  -.  P  .<_  ( ( U  .\/  V )  .\/  W ) ) 
 /\  ( ( P 
 .<_  ( ( T  .\/  U )  .\/  ( V  .\/  W ) )  /\  Q  .<_  ( ( T 
 .\/  U )  .\/  ( V  .\/  W ) ) )  /\  ( R 
 .<_  ( ( T  .\/  U )  .\/  ( V  .\/  W ) )  /\  S  .<_  ( ( T 
 .\/  U )  .\/  ( V  .\/  W ) ) ) ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( T  .\/  U )  .\/  ( V  .\/  W ) ) )
 
Theorem4atlem12 30423 Lemma for 4at 30424. Combine all four possible cases. (Contributed by NM, 11-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )
 )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R ) ) )  ->  ( (
 ( P  .\/  Q )  .\/  ( R  .\/  S ) )  .<_  ( ( T  .\/  U )  .\/  ( V  .\/  W ) )  ->  ( ( P  .\/  Q )  .\/  ( R  .\/  S ) )  =  (
 ( T  .\/  U )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4at 30424 Four atoms determine a lattice volume uniquely. Three-dimensional analog of ps-1 30288 and 3at 30301. (Contributed by NM, 11-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )
 )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R ) ) )  ->  ( (
 ( P  .\/  Q )  .\/  ( R  .\/  S ) )  .<_  ( ( T  .\/  U )  .\/  ( V  .\/  W ) )  <->  ( ( P 
 .\/  Q )  .\/  ( R  .\/  S ) )  =  ( ( T 
 .\/  U )  .\/  ( V  .\/  W ) ) ) )
 
Theorem4at2 30425 Four atoms determine a lattice volume uniquely. (Contributed by NM, 11-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ( ( ( K  e.  HL  /\  P  e.  A  /\  Q  e.  A )  /\  ( R  e.  A  /\  S  e.  A  /\  T  e.  A )  /\  ( U  e.  A  /\  V  e.  A  /\  W  e.  A )
 )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P  .\/  Q )  /\  -.  S  .<_  ( ( P  .\/  Q )  .\/  R ) ) )  ->  ( (
 ( ( P  .\/  Q )  .\/  R )  .\/  S )  .<_  ( ( ( T  .\/  U )  .\/  V )  .\/  W )  <->  ( ( ( P  .\/  Q )  .\/  R )  .\/  S )  =  ( (
 ( T  .\/  U )  .\/  V )  .\/  W ) ) )
 
Theoremlplncvrlvol2 30426 A lattice line under a lattice plane is covered by it. (Contributed by NM, 12-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |-  C  =  (  <o  `  K )   &    |-  P  =  (
 LPlanes `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( ( K  e.  HL  /\  X  e.  P  /\  Y  e.  V ) 
 /\  X  .<_  Y ) 
 ->  X C Y )
 
Theoremlplncvrlvol 30427 An element covering a lattice plane is a lattice volume and vice-versa. (Contributed by NM, 15-Jul-2012.)
 |-  B  =  ( Base `  K )   &    |-  C  =  (  <o  `  K )   &    |-  P  =  ( LPlanes `  K )   &    |-  V  =  (
 LVols `  K )   =>    |-  ( ( ( K  e.  HL  /\  X  e.  B  /\  Y  e.  B )  /\  X C Y ) 
 ->  ( X  e.  P  <->  Y  e.  V ) )
 
Theoremlvolcmp 30428 If two lattice planes are comparable, they are equal. (Contributed by NM, 12-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  ( ( K  e.  HL  /\  X  e.  V  /\  Y  e.  V ) 
 ->  ( X  .<_  Y  <->  X  =  Y ) )
 
TheoremlvolnltN 30429 Two lattice volumes cannot satisfy the less than relation. (Contributed by NM, 12-Jul-2012.) (New usage is discouraged.)
 |-  .<  =  ( lt `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  ( ( K  e.  HL  /\  X  e.  V  /\  Y  e.  V ) 
 ->  -.  X  .<  Y )
 
Theorem2lplnja 30430 The join of two different lattice planes in a lattice volume equals the volume (version of 2lplnj 30431 in terms of atoms). (Contributed by NM, 12-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  A  =  (
 Atoms `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( ( ( K  e.  HL  /\  W  e.  V )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( P  =/=  Q  /\  -.  R  .<_  ( P 
 .\/  Q ) ) ) 
 /\  ( ( S  e.  A  /\  T  e.  A  /\  U  e.  A )  /\  ( S  =/=  T  /\  -.  U  .<_  ( S  .\/  T ) ) )  /\  ( ( ( P 
 .\/  Q )  .\/  R )  .<_  W  /\  (
 ( S  .\/  T )  .\/  U )  .<_  W 
 /\  ( ( P 
 .\/  Q )  .\/  R )  =/=  ( ( S 
 .\/  T )  .\/  U ) ) )  ->  ( ( ( P 
 .\/  Q )  .\/  R )  .\/  ( ( S 
 .\/  T )  .\/  U ) )  =  W )
 
Theorem2lplnj 30431 The join of two different lattice planes in a (3-dimensional) lattice volume equals the volume. (Contributed by NM, 12-Jul-2012.)
 |-  .<_  =  ( le `  K )   &    |- 
 .\/  =  ( join `  K )   &    |-  P  =  (
 LPlanes `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( K  e.  HL  /\  ( X  e.  P  /\  Y  e.  P  /\  W  e.  V )  /\  ( X  .<_  W  /\  Y  .<_  W  /\  X  =/=  Y ) )  ->  ( X  .\/  Y )  =  W )
 
Theorem2lplnm2N 30432 The meet of two different lattice planes in a lattice volume is a lattice line. (Contributed by NM, 12-Jul-2012.) (New usage is discouraged.)
 |-  .<_  =  ( le `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  N  =  ( LLines `  K )   &    |-  P  =  (
 LPlanes `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( K  e.  HL  /\  ( X  e.  P  /\  Y  e.  P  /\  W  e.  V )  /\  ( X  .<_  W  /\  Y  .<_  W  /\  X  =/=  Y ) )  ->  ( X  ./\  Y )  e.  N )
 
Theorem2lplnmj 30433 The meet of two lattice planes is a lattice line iff their join is a lattice volume. (Contributed by NM, 13-Jul-2012.)
 |-  .\/  =  ( join `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  N  =  ( LLines `  K )   &    |-  P  =  ( LPlanes `  K )   &    |-  V  =  ( LVols `  K )   =>    |-  (
 ( K  e.  HL  /\  X  e.  P  /\  Y  e.  P )  ->  ( ( X  ./\  Y )  e.  N  <->  ( X  .\/  Y )  e.  V ) )
 
Theoremdalemkehl 30434 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  K  e.  HL )
 
Theoremdalemkelat 30435 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  K  e.  Lat )
 
Theoremdalemkeop 30436 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  K  e.  OP )
 
Theoremdalempea 30437 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  P  e.  A )
 
Theoremdalemqea 30438 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  Q  e.  A )
 
Theoremdalemrea 30439 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  R  e.  A )
 
Theoremdalemsea 30440 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  S  e.  A )
 
Theoremdalemtea 30441 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  T  e.  A )
 
Theoremdalemuea 30442 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  U  e.  A )
 
Theoremdalemyeo 30443 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  Y  e.  O )
 
Theoremdalemzeo 30444 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  Z  e.  O )
 
Theoremdalemclpjs 30445 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  C  .<_  ( P  .\/  S ) )
 
Theoremdalemclqjt 30446 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  C  .<_  ( Q  .\/  T ) )
 
Theoremdalemclrju 30447 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  C  .<_  ( R  .\/  U ) )
 
Theoremdalem-clpjq 30448 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   =>    |-  ( ph  ->  -.  C  .<_  ( P  .\/  Q ) )
 
Theoremdalemceb 30449 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  C  e.  ( Base `  K ) )
 
Theoremdalempeb 30450 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  P  e.  ( Base `  K ) )
 
Theoremdalemqeb 30451 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  Q  e.  ( Base `  K ) )
 
Theoremdalemreb 30452 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  R  e.  ( Base `  K ) )
 
Theoremdalemseb 30453 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  S  e.  ( Base `  K ) )
 
Theoremdalemteb 30454 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  T  e.  ( Base `  K ) )
 
Theoremdalemueb 30455 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  A  =  (
 Atoms `  K )   =>    |-  ( ph  ->  U  e.  ( Base `  K ) )
 
Theoremdalempjqeb 30456 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  ( P  .\/  Q )  e.  ( Base `  K ) )
 
Theoremdalemsjteb 30457 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  ( S  .\/  T )  e.  ( Base `  K ) )
 
Theoremdalemtjueb 30458 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  ( T  .\/  U )  e.  ( Base `  K ) )
 
Theoremdalemqrprot 30459 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  ( ( Q 
 .\/  R )  .\/  P )  =  ( ( P  .\/  Q )  .\/  R ) )
 
Theoremdalemyeb 30460 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  O  =  (
 LPlanes `  K )   =>    |-  ( ph  ->  Y  e.  ( Base `  K ) )
 
Theoremdalemcnes 30461 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  C  =/=  S )
 
Theoremdalempnes 30462 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  P  =/=  S )
 
Theoremdalemqnet 30463 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  Q  =/=  T )
 
Theoremdalempjsen 30464 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  ( P  .\/  S )  e.  ( LLines `  K ) )
 
Theoremdalemply 30465 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  P  .<_  Y )
 
Theoremdalemsly 30466 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  (
 ( ph  /\  Y  =  Z )  ->  S  .<_  Y )
 
Theoremdalemswapyz 30467 Lemma for dath 30547. Swap the role of planes  Y and  Z to allow reuse of analogous proofs. (Contributed by NM, 14-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   =>    |-  ( ph  ->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K ) )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )
 )  /\  ( Z  e.  O  /\  Y  e.  O )  /\  ( ( -.  C  .<_  ( S 
 .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S ) )  /\  ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q  .\/  R )  /\  -.  C  .<_  ( R  .\/  P )
 )  /\  ( C  .<_  ( S  .\/  P )  /\  C  .<_  ( T 
 .\/  Q )  /\  C  .<_  ( U  .\/  R ) ) ) ) )
 
Theoremdalemrot 30468 Lemma for dath 30547. Rotate triangles  Y  =  P Q R and  Z  =  S T U to allow reuse of analogous proofs. (Contributed by NM, 14-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  ( ph  ->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K ) )  /\  ( Q  e.  A  /\  R  e.  A  /\  P  e.  A )  /\  ( T  e.  A  /\  U  e.  A  /\  S  e.  A )
 )  /\  ( (
 ( Q  .\/  R )  .\/  P )  e.  O  /\  ( ( T  .\/  U )  .\/  S )  e.  O )  /\  ( ( -.  C  .<_  ( Q  .\/  R )  /\  -.  C  .<_  ( R  .\/  P )  /\  -.  C  .<_  ( P  .\/  Q )
 )  /\  ( -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )  /\  -.  C  .<_  ( S  .\/  T )
 )  /\  ( C  .<_  ( Q  .\/  T )  /\  C  .<_  ( R 
 .\/  U )  /\  C  .<_  ( P  .\/  S ) ) ) ) )
 
Theoremdalemrotyz 30469 Lemma for dath 30547. Rotate triangles  Y  =  P Q R and  Z  =  S T U to allow reuse of analogous proofs. (Contributed by NM, 19-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  (
 ( ph  /\  Y  =  Z )  ->  ( ( Q  .\/  R )  .\/  P )  =  ( ( T  .\/  U )  .\/  S ) )
 
Theoremdalem1 30470 Lemma for dath 30547. Show the lines  P S and  Q T are different. (Contributed by NM, 9-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  ( P  .\/  S )  =/=  ( Q 
 .\/  T ) )
 
Theoremdalemcea 30471 Lemma for dath 30547. Frequently-used utility lemma. Here we show that  C must be an atom. This is an assumption in most presentations of Desargue's theorem; instead, we assume only the  C is a lattice element, in order to make later substitutions for  C easier. (Contributed by NM, 23-Sep-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  C  e.  A )
 
Theoremdalem2 30472 Lemma for dath 30547. Show the lines  P Q and  S T form a plane. (Contributed by NM, 11-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  ( ( P 
 .\/  Q )  .\/  ( S  .\/  T ) )  e.  O )
 
Theoremdalemdea 30473 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 11-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   =>    |-  ( ph  ->  D  e.  A )
 
Theoremdalemeea 30474 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 11-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   =>    |-  ( ph  ->  E  e.  A )
 
Theoremdalem3 30475 Lemma for dalemdnee 30477. (Contributed by NM, 10-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   =>    |-  ( ( ph  /\  D  =/=  Q ) 
 ->  D  =/=  E )
 
Theoremdalem4 30476 Lemma for dalemdnee 30477. (Contributed by NM, 10-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   =>    |-  ( ( ph  /\  D  =/=  T ) 
 ->  D  =/=  E )
 
Theoremdalemdnee 30477 Lemma for dath 30547. Axis of perspectivity points  D and  E are different. (Contributed by NM, 10-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   =>    |-  ( ph  ->  D  =/=  E )
 
Theoremdalem5 30478 Lemma for dath 30547. Atom  U (in plane  Z  =  S T U) belongs to the 3-dimensional volume formed by  Y and 
C. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ph  ->  U  .<_  W )
 
Theoremdalem6 30479 Lemma for dath 30547. Analog of dalem5 30478 for  S. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ph  ->  S  .<_  W )
 
Theoremdalem7 30480 Lemma for dath 30547. Analog of dalem5 30478 for  T. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ph  ->  T  .<_  W )
 
Theoremdalem8 30481 Lemma for dath 30547. Plane  Z belongs to the 3-dimensional space. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ph  ->  Z  .<_  W )
 
Theoremdalem-cly 30482 Lemma for dalem9 30483. Center of perspectivity  C is not in plane  Y (when  Y and  Z are different planes). (Contributed by NM, 13-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  (
 ( ph  /\  Y  =/=  Z )  ->  -.  C  .<_  Y )
 
Theoremdalem9 30483 Lemma for dath 30547. Since  -.  C  .<_  Y, the join  Y  .\/  C forms a 3-dimensional space. (Contributed by NM, 20-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  V  =  ( LVols `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ( ph  /\  Y  =/=  Z )  ->  W  e.  V )
 
Theoremdalem10 30484 Lemma for dath 30547. Atom  D belongs to the axis of perspectivity  X. (Contributed by NM, 19-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  X  =  ( Y  ./\  Z )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   =>    |-  ( ph  ->  D  .<_  X )
 
Theoremdalem11 30485 Lemma for dath 30547. Analog of dalem10 30484 for  E. (Contributed by NM, 23-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  X  =  ( Y  ./\  Z )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   =>    |-  ( ph  ->  E  .<_  X )
 
Theoremdalem12 30486 Lemma for dath 30547. Analog of dalem10 30484 for  F. (Contributed by NM, 11-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  X  =  ( Y  ./\  Z )   &    |-  F  =  ( ( R  .\/  P )  ./\  ( U  .\/  S ) )   =>    |-  ( ph  ->  F  .<_  X )
 
Theoremdalem13 30487 Lemma for dalem14 30488. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ( ph  /\  Y  =/=  Z )  ->  ( Y  .\/  Z )  =  W )
 
Theoremdalem14 30488 Lemma for dath 30547. Planes  Y and 
Z form a 3-dimensional space (when they are different). (Contributed by NM, 22-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  V  =  ( LVols `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  W  =  ( Y  .\/  C )   =>    |-  ( ( ph  /\  Y  =/=  Z )  ->  ( Y  .\/  Z )  e.  V )
 
Theoremdalem15 30489 Lemma for dath 30547. The axis of perspectivity  X is a line. (Contributed by NM, 21-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  N  =  ( LLines `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  X  =  ( Y  ./\  Z )   =>    |-  ( ( ph  /\  Y  =/=  Z )  ->  X  e.  N )
 
Theoremdalem16 30490 Lemma for dath 30547. The atoms  D,  E, and  F form a line of perspectivity. This is Desargue's Theorem for the special case where planes  Y and  Z are different. (Contributed by NM, 7-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  ./\  =  ( meet `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   &    |-  D  =  ( ( P  .\/  Q )  ./\  ( S  .\/  T ) )   &    |-  E  =  ( ( Q  .\/  R )  ./\  ( T  .\/  U ) )   &    |-  F  =  ( ( R  .\/  P )  ./\  ( U  .\/  S ) )   =>    |-  ( ( ph  /\  Y  =/=  Z ) 
 ->  F  .<_  ( D  .\/  E ) )
 
Theoremdalem17 30491 Lemma for dath 30547. When planes  Y and 
Z are equal, the center of perspectivity  C is in  Y. (Contributed by NM, 1-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  (
 ( ph  /\  Y  =  Z )  ->  C  .<_  Y )
 
Theoremdalem18 30492* Lemma for dath 30547. Show that a dummy atom  c exists outside of the  Y and  Z planes (when those planes are equal). This requires that the projective space be 3-dimensional. (Desargue's theorem doesn't always hold in 2 dimensions.) (Contributed by NM, 29-Jul-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   =>    |-  ( ph  ->  E. c  e.  A  -.  c  .<_  Y )
 
Theoremdalem19 30493* Lemma for dath 30547. Show that a second dummy atom  d exists outside of the  Y and  Z planes (when those planes are equal). (Contributed by NM, 15-Aug-2012.)
 |-  ( ph 
 <->  ( ( ( K  e.  HL  /\  C  e.  ( Base `  K )
 )  /\  ( P  e.  A  /\  Q  e.  A  /\  R  e.  A )  /\  ( S  e.  A  /\  T  e.  A  /\  U  e.  A ) )  /\  ( Y  e.  O  /\  Z  e.  O )  /\  (
 ( -.  C  .<_  ( P  .\/  Q )  /\  -.  C  .<_  ( Q 
 .\/  R )  /\  -.  C  .<_  ( R  .\/  P ) )  /\  ( -.  C  .<_  ( S  .\/  T )  /\  -.  C  .<_  ( T  .\/  U )  /\  -.  C  .<_  ( U  .\/  S )
 )  /\  ( C  .<_  ( P  .\/  S )  /\  C  .<_  ( Q 
 .\/  T )  /\  C  .<_  ( R  .\/  U ) ) ) ) )   &    |-  .<_  =  ( le `  K )   &    |-  .\/  =  ( join `  K )   &    |-  A  =  ( Atoms `  K )   &    |-  O  =  ( LPlanes `  K )   &    |-  Y  =  ( ( P  .\/  Q )  .\/  R )   &    |-  Z  =  ( ( S  .\/  T )  .\/  U )   =>    |-  (
 ( ( ( ph  /\  Y  =  Z ) 
 /\  c  e.  A )  /\  -.  c  .<_  Y )  ->  E. d  e.  A  ( d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d )
 ) )
 
Theoremdalemccea 30494 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  c  e.  A )
 
Theoremdalemddea 30495 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  d  e.  A )
 
Theoremdalem-ccly 30496 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  -.  c  .<_  Y )
 
Theoremdalem-ddly 30497 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  -.  d  .<_  Y )
 
Theoremdalemccnedd 30498 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  c  =/=  d )
 
Theoremdalemclccjdd 30499 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y  /\  C  .<_  ( c  .\/  d
 ) ) ) )   =>    |-  ( ps  ->  C  .<_  ( c  .\/  d )
 )
 
Theoremdalemcceb 30500 Lemma for dath 30547. Frequently-used utility lemma. (Contributed by NM, 15-Aug-2012.)
 |-  ( ps 
 <->  ( ( c  e.  A  /\  d  e.  A )  /\  -.  c  .<_  Y  /\  (
 d  =/=  c  /\  -.  d  .<_  Y