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Theorem isoeq5 5945
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 5573 . . 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 5335 . 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 5335 . 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 1397   A.wral 2510   class class class wbr 4088   -1-1-onto->wf1o 5325   ` cfv 5326    Isom wiso 5327
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 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-11 1554  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213
This theorem depends on definitions:  df-bi 117  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-in 3206  df-ss 3213  df-f 5330  df-f1 5331  df-fo 5332  df-f1o 5333  df-isom 5335
This theorem is referenced by:  isores3  5955  ordiso  7234  zfz1isolem1  11103  zfz1iso  11104
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