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Theorem ifbid 3377
Description: Equivalence deduction for conditional operators. (Contributed by NM, 18-Apr-2005.)
Hypothesis
Ref Expression
ifbid.1 (𝜑 → (𝜓𝜒))
Assertion
Ref Expression
ifbid (𝜑 → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐴, 𝐵))

Proof of Theorem ifbid
StepHypRef Expression
1 ifbid.1 . 2 (𝜑 → (𝜓𝜒))
2 ifbi 3376 . 2 ((𝜓𝜒) → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐴, 𝐵))
31, 2syl 14 1 (𝜑 → if(𝜓, 𝐴, 𝐵) = if(𝜒, 𝐴, 𝐵))
Colors of variables: wff set class
Syntax hints:  wi 4  wb 102   = wceq 1259  ifcif 3359
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-in1 554  ax-in2 555  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-11 1413  ax-4 1416  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038
This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-if 3360
This theorem is referenced by:  ifbieq1d  3378  ifbieq2d  3380  ifbieq12d  3382  sumeq1  10105
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