Theorem dfifp4dc 996

Description: Alternate definition of the conditional operator for propositions. (Contributed by BJ, 30-Sep-2019.)

Assertion

Ref	Expression
dfifp4dc	⊢ (DECID 𝜑 → (if-(𝜑, 𝜓, 𝜒) ↔ ((¬ 𝜑 ∨ 𝜓) ∧ (𝜑 ∨ 𝜒))))

Proof of Theorem dfifp4dc

Step	Hyp	Ref	Expression
1		dfifp3dc 995	. 2 ⊢ (DECID 𝜑 → (if-(𝜑, 𝜓, 𝜒) ↔ ((𝜑 → 𝜓) ∧ (𝜑 ∨ 𝜒))))
2		imordc 909	. . 3 ⊢ (DECID 𝜑 → ((𝜑 → 𝜓) ↔ (¬ 𝜑 ∨ 𝜓)))
3	2	anbi1d 469	. 2 ⊢ (DECID 𝜑 → (((𝜑 → 𝜓) ∧ (𝜑 ∨ 𝜒)) ↔ ((¬ 𝜑 ∨ 𝜓) ∧ (𝜑 ∨ 𝜒))))
4	1, 3	bitrd 188	1 ⊢ (DECID 𝜑 → (if-(𝜑, 𝜓, 𝜒) ↔ ((¬ 𝜑 ∨ 𝜓) ∧ (𝜑 ∨ 𝜒))))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 104   ↔ wb 105   ∨ wo 720  DECID wdc 846  if-wif 990

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721

This theorem depends on definitions:  df-bi 117  df-dc 847  df-ifp 991

This theorem is referenced by:  anifpdc  999