Metamath Proof Explorer
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 ) |