Metamath Proof Explorer


Theorem bj-stdpc5

Description: More direct proof of stdpc5 . (Contributed by BJ, 15-Sep-2018) (Proof modification is discouraged.)

Ref Expression
Hypothesis bj-stdpc5.1 ⊢ Ⅎ x φ
Assertion bj-stdpc5 ⊢ ∀ x φ → ψ → φ → ∀ x ψ

Proof

Step Hyp Ref Expression
1 bj-stdpc5.1 ⊢ Ⅎ x φ
2 stdpc5t ⊢ Ⅎ x φ → ∀ x φ → ψ → φ → ∀ x ψ
3 1 2 ax-mp ⊢ ∀ x φ → ψ → φ → ∀ x ψ