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Theorem isoeq5 5874
Description: Equality theorem for isomorphisms. (Contributed by NM, 17-May-2004.)
Assertion
Ref Expression
isoeq5  |-  ( B  =  C  ->  ( H  Isom  R ,  S  ( A ,  B )  <-> 
H  Isom  R ,  S  ( A ,  C ) ) )

Proof of Theorem isoeq5
Dummy variables  x  y are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 f1oeq3 5512 . . 3  |-  ( B  =  C  ->  ( H : A -1-1-onto-> B  <->  H : A -1-1-onto-> C ) )
21anbi1d 465 . 2  |-  ( B  =  C  ->  (
( H : A -1-1-onto-> B  /\  A. x  e.  A  A. y  e.  A  ( x R y  <-> 
( H `  x
) S ( H `
 y ) ) )  <->  ( H : A
-1-1-onto-> C  /\  A. x  e.  A  A. y  e.  A  ( x R y  <->  ( H `  x ) S ( H `  y ) ) ) ) )
3 df-isom 5280 . 2  |-  ( H 
Isom  R ,  S  ( A ,  B )  <-> 
( H : A -1-1-onto-> B  /\  A. x  e.  A  A. y  e.  A  ( x R y  <-> 
( H `  x
) S ( H `
 y ) ) ) )
4 df-isom 5280 . 2  |-  ( H 
Isom  R ,  S  ( A ,  C )  <-> 
( H : A -1-1-onto-> C  /\  A. x  e.  A  A. y  e.  A  ( x R y  <-> 
( H `  x
) S ( H `
 y ) ) ) )
52, 3, 43bitr4g 223 1  |-  ( B  =  C  ->  ( H  Isom  R ,  S  ( A ,  B )  <-> 
H  Isom  R ,  S  ( A ,  C ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    <-> wb 105    = wceq 1373   A.wral 2484   class class class wbr 4044   -1-1-onto->wf1o 5270   ` cfv 5271    Isom wiso 5272
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-11 1529  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187
This theorem depends on definitions:  df-bi 117  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-in 3172  df-ss 3179  df-f 5275  df-f1 5276  df-fo 5277  df-f1o 5278  df-isom 5280
This theorem is referenced by:  isores3  5884  ordiso  7138  zfz1isolem1  10985  zfz1iso  10986
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