Metamath Proof Explorer


Axiom ax-7d

Description: Distinct variable version of ax-11 . (Contributed by Mario Carneiro, 14-Aug-2015)

Ref Expression
Assertion ax-7d ( ∀ 𝑥 ∀ 𝑦 𝜑 → ∀ 𝑦 ∀ 𝑥 𝜑 )

Detailed syntax breakdown

Step Hyp Ref Expression
0 vx ⊢ 𝑥
1 vy ⊢ 𝑦
2 wph ⊢ 𝜑
3 2 1 wal ⊢ ∀ 𝑦 𝜑
4 3 0 wal ⊢ ∀ 𝑥 ∀ 𝑦 𝜑
5 2 0 wal ⊢ ∀ 𝑥 𝜑
6 5 1 wal ⊢ ∀ 𝑦 ∀ 𝑥 𝜑
7 4 6 wi ⊢ ( ∀ 𝑥 ∀ 𝑦 𝜑 → ∀ 𝑦 ∀ 𝑥 𝜑 )