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Theorem ifbieq2i 3495
Description: Equivalence/equality inference for conditional operators. (Contributed by Paul Chapman, 22-Jun-2011.)
Hypotheses
Ref Expression
ifbieq2i.1  |-  ( ph  <->  ps )
ifbieq2i.2  |-  A  =  B
Assertion
Ref Expression
ifbieq2i  |-  if (
ph ,  C ,  A )  =  if ( ps ,  C ,  B )

Proof of Theorem ifbieq2i
StepHypRef Expression
1 ifbieq2i.1 . . 3  |-  ( ph  <->  ps )
2 ifbi 3492 . . 3  |-  ( (
ph 
<->  ps )  ->  if ( ph ,  C ,  A )  =  if ( ps ,  C ,  A ) )
31, 2ax-mp 5 . 2  |-  if (
ph ,  C ,  A )  =  if ( ps ,  C ,  A )
4 ifbieq2i.2 . . 3  |-  A  =  B
5 ifeq2 3478 . . 3  |-  ( A  =  B  ->  if ( ps ,  C ,  A )  =  if ( ps ,  C ,  B ) )
64, 5ax-mp 5 . 2  |-  if ( ps ,  C ,  A )  =  if ( ps ,  C ,  B )
73, 6eqtri 2160 1  |-  if (
ph ,  C ,  A )  =  if ( ps ,  C ,  B )
Colors of variables: wff set class
Syntax hints:    <-> wb 104    = wceq 1331   ifcif 3474
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 603  ax-in2 604  ax-io 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2121
This theorem depends on definitions:  df-bi 116  df-tru 1334  df-nf 1437  df-sb 1736  df-clab 2126  df-cleq 2132  df-clel 2135  df-nfc 2270  df-rab 2425  df-v 2688  df-un 3075  df-if 3475
This theorem is referenced by:  ifbieq12i  3497  gcdcom  11662  gcdass  11703  lcmcom  11745  lcmass  11766
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