Metamath Proof Explorer


Theorem bj-cbv3hv2

Description: Version of cbv3h with two disjoint variable conditions, which does not require ax-11 nor ax-13 . (Contributed by BJ, 24-Jun-2019) (Proof modification is discouraged.)

Ref Expression
Hypotheses bj-cbv3hv2.nf ⊢ ( 𝜓 → ∀ 𝑥 𝜓 )
bj-cbv3hv2.1 ⊢ ( 𝑥 = 𝑦 → ( 𝜑 → 𝜓 ) )
Assertion bj-cbv3hv2 ( ∀ 𝑥 𝜑 → ∀ 𝑦 𝜓 )

Proof

Step Hyp Ref Expression
1 bj-cbv3hv2.nf ⊢ ( 𝜓 → ∀ 𝑥 𝜓 )
2 bj-cbv3hv2.1 ⊢ ( 𝑥 = 𝑦 → ( 𝜑 → 𝜓 ) )
3 1 nf5i ⊢ Ⅎ 𝑥 𝜓
4 3 2 cbv3v2 ⊢ ( ∀ 𝑥 𝜑 → ∀ 𝑦 𝜓 )