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Theorem dfifp2 1062
Description: Alternate definition of the conditional operator for propositions. The value of if-(𝜑, 𝜓, 𝜒) is "if 𝜑 then 𝜓, and if not 𝜑 then 𝜒". This is the definition used in Section II.24 of [Church] p. 129 (Definition D12 page 132) (see comment of df-ifp 1061). (Contributed by BJ, 22-Jun-2019.)
Assertion
Ref Expression
dfifp2 (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑𝜓) ∧ (¬ 𝜑𝜒)))

Proof of Theorem dfifp2
StepHypRef Expression
1 df-ifp 1061 . 2 (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑𝜓) ∨ (¬ 𝜑𝜒)))
2 cases2 1045 . 2 (((𝜑𝜓) ∨ (¬ 𝜑𝜒)) ↔ ((𝜑𝜓) ∧ (¬ 𝜑𝜒)))
31, 2bitri 275 1 (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑𝜓) ∧ (¬ 𝜑𝜒)))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 205  wa 395  wo 844  if-wif 1060
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-ifp 1061
This theorem is referenced by:  dfifp3  1063  dfifp5  1065  ifpdfbi  1068  ifpnOLD  1072  ifpimpda  1080  revwlk  34579  ifpbi2  42681  ifpbi3  42682  ifpbi1  42691  ifpbi12  42702  ifpbi13  42703  ifpimimb  42718  ifpororb  42719  ifpbibib  42724  frege54cor0a  43077
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