Theorem ifbieq12d 3421

Description: Equivalence deduction for conditional operators. (Contributed by Jeff Madsen, 2-Sep-2009.)

Hypotheses

Ref	Expression
ifbieq12d.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))
ifbieq12d.2	⊢ (𝜑 → 𝐴 = 𝐶)
ifbieq12d.3	⊢ (𝜑 → 𝐵 = 𝐷)

Assertion

Ref	Expression
ifbieq12d	⊢ (𝜑 → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐶, 𝐷))

Proof of Theorem ifbieq12d

Step	Hyp	Ref	Expression
1		ifbieq12d.1	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2	1	ifbid 3416	. 2 ⊢ (𝜑 → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐴, 𝐵))
3		ifbieq12d.2	. . 3 ⊢ (𝜑 → 𝐴 = 𝐶)
4		ifbieq12d.3	. . 3 ⊢ (𝜑 → 𝐵 = 𝐷)
5	3, 4	ifeq12d 3414	. 2 ⊢ (𝜑 → if(𝜒, 𝐴, 𝐵) = if(𝜒, 𝐶, 𝐷))
6	2, 5	eqtrd 2121	1 ⊢ (𝜑 → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐶, 𝐷))

Syntax hints:   → wi 4   ↔ wb 104   = wceq 1290  ifcif 3397

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 580  ax-in2 581  ax-io 666  ax-5 1382  ax-7 1383  ax-gen 1384  ax-ie1 1428  ax-ie2 1429  ax-8 1441  ax-10 1442  ax-11 1443  ax-i12 1444  ax-bndl 1445  ax-4 1446  ax-17 1465  ax-i9 1469  ax-ial 1473  ax-i5r 1474  ax-ext 2071

This theorem depends on definitions:  df-bi 116  df-tru 1293  df-nf 1396  df-sb 1694  df-clab 2076  df-cleq 2082  df-clel 2085  df-nfc 2218  df-rab 2369  df-v 2622  df-un 3004  df-if 3398

This theorem is referenced by:  updjudhcoinlf  6825  updjudhcoinrg  6826  iseqf1olemqval  9970  iseqf1olemqk  9977  seq3f1olemqsum  9983  exp3val  10011  cvgratz  10980  eucalgval2  11367  ressid2  11607  ressval2  11608