Theorem dfifp7 1085

Description: Alternate definition of the conditional operator for propositions. (Contributed by BJ, 2-Oct-2019.)

Assertion

Ref	Expression
dfifp7	⊢ (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜒 → 𝜑) → (𝜑 ∧ 𝜓)))

Proof of Theorem dfifp7

Step	Hyp	Ref	Expression
1		orcom 884	. 2 ⊢ (((𝜑 ∧ 𝜓) ∨ ¬ (𝜒 → 𝜑)) ↔ (¬ (𝜒 → 𝜑) ∨ (𝜑 ∧ 𝜓)))
2		dfifp6 1084	. 2 ⊢ (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑 ∧ 𝜓) ∨ ¬ (𝜒 → 𝜑)))
3		imor 867	. 2 ⊢ (((𝜒 → 𝜑) → (𝜑 ∧ 𝜓)) ↔ (¬ (𝜒 → 𝜑) ∨ (𝜑 ∧ 𝜓)))
4	1, 2, 3	3bitr4i 306	1 ⊢ (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜒 → 𝜑) → (𝜑 ∧ 𝜓)))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861  if-wif 1078

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-ifp 1079

This theorem is used by:  wl-2mintru2  38177