Metamath Proof Explorer


Theorem axi10

Description: Axiom of Quantifier Substitution (intuitionistic logic axiom ax-10). This is just axc11n by another name. (Contributed by Jim Kingdon, 31-Dec-2017) (New usage is discouraged.)

Ref Expression
Assertion axi10 x x = y y y = x

Proof

Step Hyp Ref Expression
1 axc11n x x = y y y = x