Metamath Proof Explorer


Theorem uun123

Description: A deduction unionizing a non-unionized collection of virtual hypotheses. (Contributed by Alan Sare, 4-Feb-2017) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis uun123.1 ( ( 𝜑𝜒𝜓 ) → 𝜃 )
Assertion uun123 ( ( 𝜑𝜓𝜒 ) → 𝜃 )

Proof

Step Hyp Ref Expression
1 uun123.1 ( ( 𝜑𝜒𝜓 ) → 𝜃 )
2 3ancomb ( ( 𝜑𝜒𝜓 ) ↔ ( 𝜑𝜓𝜒 ) )
3 2 1 sylbir ( ( 𝜑𝜓𝜒 ) → 𝜃 )