Metamath Proof Explorer


Theorem syl22anc

Description: Syllogism combined with contraction. (Contributed by NM, 11-Mar-2012)

Ref Expression
Hypotheses syl12anc.1 ( 𝜑𝜓 )
syl12anc.2 ( 𝜑𝜒 )
syl12anc.3 ( 𝜑𝜃 )
syl22anc.4 ( 𝜑𝜏 )
syl22anc.5 ( ( ( 𝜓𝜒 ) ∧ ( 𝜃𝜏 ) ) → 𝜂 )
Assertion syl22anc ( 𝜑𝜂 )

Proof

Step Hyp Ref Expression
1 syl12anc.1 ( 𝜑𝜓 )
2 syl12anc.2 ( 𝜑𝜒 )
3 syl12anc.3 ( 𝜑𝜃 )
4 syl22anc.4 ( 𝜑𝜏 )
5 syl22anc.5 ( ( ( 𝜓𝜒 ) ∧ ( 𝜃𝜏 ) ) → 𝜂 )
6 1 2 jca ( 𝜑 → ( 𝜓𝜒 ) )
7 6 3 4 5 syl12anc ( 𝜑𝜂 )