Metamath Proof Explorer


Theorem bnj1254

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

Ref Expression
Hypothesis bnj1254.1 ( 𝜑 ↔ ( 𝜓𝜒𝜃𝜏 ) )
Assertion bnj1254 ( 𝜑𝜏 )

Proof

Step Hyp Ref Expression
1 bnj1254.1 ( 𝜑 ↔ ( 𝜓𝜒𝜃𝜏 ) )
2 id ( 𝜏𝜏 )
3 2 bnj708 ( ( 𝜓𝜒𝜃𝜏 ) → 𝜏 )
4 1 3 sylbi ( 𝜑𝜏 )