Metamath Proof Explorer


Theorem bnj534

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

Ref Expression
Hypothesis bnj534.1 χxφψ
Assertion bnj534 χxφψ

Proof

Step Hyp Ref Expression
1 bnj534.1 χxφψ
2 19.41v xφψxφψ
3 1 2 sylibr χxφψ