Theorem ax7dgen 1719

Description: Degenerate instance of ax-7 1734 where bundled variables x and y have a common substitution. Uses only Tarski's FOL axiom schemes. (Contributed by NM, 13-Apr-2017.)

Assertion

Ref	Expression
ax7dgen	⊢ (∀x∀xφ → ∀x∀xφ)

Proof of Theorem ax7dgen

Step	Hyp	Ref	Expression
1		id 19	1 ⊢ (∀x∀xφ → ∀x∀xφ)

This proof depends on syntax axioms:   → wi 4  ∀wal 1540

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7

This theorem is used by: (None)