Metamath Proof Explorer


Theorem bnj1350

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypothesis bnj1350.1 χxχ
Assertion bnj1350 φψχxφψχ

Proof

Step Hyp Ref Expression
1 bnj1350.1 χxχ
2 ax-5 φxφ
3 ax-5 ψxψ
4 2 3 1 hb3an φψχxφψχ