Metamath Proof Explorer


Theorem bj-ala1i

Description: Add an antecedent in a universally quantified formula. Inference associated with ala1 . (Contributed by BJ, 6-Oct-2018)

Ref Expression
Hypothesis bj-ala1i.1 x φ
Assertion bj-ala1i x ψ φ

Proof

Step Hyp Ref Expression
1 bj-ala1i.1 x φ
2 ala1 x φ x ψ φ
3 1 2 ax-mp x ψ φ