Theorem ifbieq1d 3350

Description: Equivalence/equality deduction for conditional operators. (Contributed by JJ, 25-Sep-2018.)

Hypotheses

Ref	Expression
ifbieq1d.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))
ifbieq1d.2	⊢ (𝜑 → 𝐴 = 𝐵)

Assertion

Ref	Expression
ifbieq1d	⊢ (𝜑 → if(𝜓, 𝐴, 𝐶) = if(𝜒, 𝐵, 𝐶))

Proof of Theorem ifbieq1d

Step	Hyp	Ref	Expression
1		ifbieq1d.1	. . 3 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2	1	ifbid 3349	. 2 ⊢ (𝜑 → if(𝜓, 𝐴, 𝐶) = if(𝜒, 𝐴, 𝐶))
3		ifbieq1d.2	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
4	3	ifeq1d 3345	. 2 ⊢ (𝜑 → if(𝜒, 𝐴, 𝐶) = if(𝜒, 𝐵, 𝐶))
5	2, 4	eqtrd 2072	1 ⊢ (𝜑 → if(𝜓, 𝐴, 𝐶) = if(𝜒, 𝐵, 𝐶))

Syntax hints:   → wi 4   ↔ wb 98   = wceq 1243  ifcif 3331

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-rab 2315  df-v 2559  df-un 2922  df-if 3332

This theorem is referenced by: (None)