Theorem pm4.71d 393

Description: Deduction converting an implication to a biconditional with conjunction. Deduction from Theorem *4.71 of [WhiteheadRussell] p. 120. (Contributed by Mario Carneiro, 25-Dec-2016.)

Hypothesis

Ref	Expression
pm4.71rd.1	⊢ (𝜑 → (𝜓 → 𝜒))

Assertion

Ref	Expression
pm4.71d	⊢ (𝜑 → (𝜓 ↔ (𝜓 ∧ 𝜒)))

Proof of Theorem pm4.71d

Step	Hyp	Ref	Expression
1		pm4.71rd.1	. 2 ⊢ (𝜑 → (𝜓 → 𝜒))
2		pm4.71 389	. 2 ⊢ ((𝜓 → 𝜒) ↔ (𝜓 ↔ (𝜓 ∧ 𝜒)))
3	1, 2	sylib 122	1 ⊢ (𝜑 → (𝜓 ↔ (𝜓 ∧ 𝜒)))

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108

This theorem depends on definitions:  df-bi 117

This theorem is referenced by:  difin2  3399  resopab2  4956  fcnvres  5401  resoprab2  5974  cndis  13826  cnpdis  13827  blpnf  13985