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Theorem ifpnot23 38363
Description: Negation of conditional logical operator. (Contributed by RP, 18-Apr-2020.)
Assertion
Ref Expression
ifpnot23 (¬ if-(𝜑, 𝜓, 𝜒) ↔ if-(𝜑, ¬ 𝜓, ¬ 𝜒))

Proof of Theorem ifpnot23
StepHypRef Expression
1 ianor 993 . . . 4 (¬ (𝜑𝜓) ↔ (¬ 𝜑 ∨ ¬ 𝜓))
2 pm4.55 999 . . . 4 (¬ (¬ 𝜑𝜒) ↔ (𝜑 ∨ ¬ 𝜒))
31, 2anbi12i 613 . . 3 ((¬ (𝜑𝜓) ∧ ¬ (¬ 𝜑𝜒)) ↔ ((¬ 𝜑 ∨ ¬ 𝜓) ∧ (𝜑 ∨ ¬ 𝜒)))
4 ioran 995 . . 3 (¬ ((𝜑𝜓) ∨ (¬ 𝜑𝜒)) ↔ (¬ (𝜑𝜓) ∧ ¬ (¬ 𝜑𝜒)))
5 dfifp4 1080 . . 3 (if-(𝜑, ¬ 𝜓, ¬ 𝜒) ↔ ((¬ 𝜑 ∨ ¬ 𝜓) ∧ (𝜑 ∨ ¬ 𝜒)))
63, 4, 53bitr4i 293 . 2 (¬ ((𝜑𝜓) ∨ (¬ 𝜑𝜒)) ↔ if-(𝜑, ¬ 𝜓, ¬ 𝜒))
7 df-ifp 1077 . 2 (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑𝜓) ∨ (¬ 𝜑𝜒)))
86, 7xchnxbir 323 1 (¬ if-(𝜑, 𝜓, 𝜒) ↔ if-(𝜑, ¬ 𝜓, ¬ 𝜒))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wb 197  wa 383  wo 863  if-wif 1076
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 198  df-an 384  df-or 864  df-ifp 1077
This theorem is referenced by:  ifpnotnotb  38364  ifpnorcor  38365  ifpnancor  38366  ifpnot23b  38367  ifpnot23c  38369  ifpnot23d  38370  ifpdfnan  38371  ifpdfxor  38372  ifpor123g  38393
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