Theorem ifeq1d 3623

Description: Equality deduction for conditional operator. (Contributed by NM, 16-Feb-2005.)

Hypothesis

Ref	Expression
ifeq1d.1	|- ( ph -> A = B )

Assertion

Ref	Expression
ifeq1d	|- ( ph -> if ( ps , A , C ) = if ( ps , B , C ) )

Proof of Theorem ifeq1d

Step	Hyp	Ref	Expression
1		ifeq1d.1	. 2 |- ( ph -> A = B )
2		ifeq1 3608	. 2 |- ( A = B -> if ( ps , A , C ) = if ( ps , B , C ) )
3	1, 2	syl 14	1 |- ( ph -> if ( ps , A , C ) = if ( ps , B , C ) )

Syntax hints:   -> wi 4   = wceq 1397   ifcif 3605

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-io 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  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-tru 1400  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-rab 2519  df-v 2804  df-un 3204  df-if 3606

This theorem is referenced by:  ifeq12d  3625  ifbieq1d  3628  ifeq1dadc  3636  iseqf1olemjpcl  10771  iseqf1olemqpcl  10772  iseqf1olemfvp  10773  seq3f1olemqsum  10776  seq3f1olemp  10778  summodc  11962  fsum3  11966  fsum3ser  11976  isumlessdc  12075  prodeq2w  12135  prodmodc  12157  fprodseq  12162  prodssdc  12168  subgmulg  13793  lgsval  15752