Metamath Proof Explorer


Theorem pm4.45im

Description: Conjunction with implication. Compare Theorem *4.45 of WhiteheadRussell p. 119. (Contributed by NM, 17-May-1998)

Ref Expression
Assertion pm4.45im ⊢ φ ↔ φ ∧ ψ → φ

Proof

Step Hyp Ref Expression
1 ax-1 ⊢ φ → ψ → φ
2 1 pm4.71i ⊢ φ ↔ φ ∧ ψ → φ