Metamath Proof Explorer


Theorem nf5rd

Description: Consequence of the definition of not-free in a context. (Contributed by Mario Carneiro, 11-Aug-2016)

Ref Expression
Hypothesis nf5rd.1 ( 𝜑 → Ⅎ 𝑥 𝜓 )
Assertion nf5rd ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) )

Proof

Step Hyp Ref Expression
1 nf5rd.1 ( 𝜑 → Ⅎ 𝑥 𝜓 )
2 nf5r ( Ⅎ 𝑥 𝜓 → ( 𝜓 → ∀ 𝑥 𝜓 ) )
3 1 2 syl ( 𝜑 → ( 𝜓 → ∀ 𝑥 𝜓 ) )