Theorem ifpnim2 41004

Description: Restate negated implication as conditional logic operator. (Contributed by RP, 25-Apr-2020.)

Assertion

Ref	Expression
ifpnim2	⊢ (¬ (𝜑 → 𝜓) ↔ if-(𝜓, ¬ 𝜓, 𝜑))

Proof of Theorem ifpnim2

Step	Hyp	Ref	Expression
1		ifpnot23c 40989	. 2 ⊢ (¬ if-(𝜓, 𝜓, ¬ 𝜑) ↔ if-(𝜓, ¬ 𝜓, 𝜑))
2		ifpim4 41003	. 2 ⊢ ((𝜑 → 𝜓) ↔ if-(𝜓, 𝜓, ¬ 𝜑))
3	1, 2	xchnxbir 332	1 ⊢ (¬ (𝜑 → 𝜓) ↔ if-(𝜓, ¬ 𝜓, 𝜑))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205  if-wif 1059

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 844  df-ifp 1060

This theorem is referenced by: (None)