Metamath Proof Explorer


Theorem bnj1232

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

Ref Expression
Hypothesis bnj1232.1 φψχθτ
Assertion bnj1232 φψ

Proof

Step Hyp Ref Expression
1 bnj1232.1 φψχθτ
2 bnj642 ψχθτψ
3 1 2 sylbi φψ