Metamath Proof Explorer


Theorem bnj1345

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

Ref Expression
Hypotheses bnj1345.1 φ x ψ χ
bnj1345.2 θ φ ψ χ
bnj1345.3 φ x φ
Assertion bnj1345 φ x θ

Proof

Step Hyp Ref Expression
1 bnj1345.1 φ x ψ χ
2 bnj1345.2 θ φ ψ χ
3 bnj1345.3 φ x φ
4 1 3 bnj1275 φ x φ ψ χ
5 4 2 bnj1198 φ x θ