Metamath Proof Explorer


Theorem sylancom

Description: Syllogism inference with commutation of antecedents. (Contributed by NM, 2-Jul-2008)

Ref Expression
Hypotheses sylancom.1 ( ( 𝜑𝜓 ) → 𝜒 )
sylancom.2 ( ( 𝜒𝜓 ) → 𝜃 )
Assertion sylancom ( ( 𝜑𝜓 ) → 𝜃 )

Proof

Step Hyp Ref Expression
1 sylancom.1 ( ( 𝜑𝜓 ) → 𝜒 )
2 sylancom.2 ( ( 𝜒𝜓 ) → 𝜃 )
3 simpr ( ( 𝜑𝜓 ) → 𝜓 )
4 1 3 2 syl2anc ( ( 𝜑𝜓 ) → 𝜃 )