Metamath Proof Explorer


Theorem jccil

Description: Inference conjoining a consequent of a consequent to the left of the consequent in an implication. Remark: One can also prove this theorem using syl and jca (as done in jccir ), which would be 4 bytes shorter, but one step longer than the current proof. (Proof modification is discouraged.) (Contributed by AV, 20-Aug-2019)

Ref Expression
Hypotheses jccir.1 ( 𝜑𝜓 )
jccir.2 ( 𝜓𝜒 )
Assertion jccil ( 𝜑 → ( 𝜒𝜓 ) )

Proof

Step Hyp Ref Expression
1 jccir.1 ( 𝜑𝜓 )
2 jccir.2 ( 𝜓𝜒 )
3 1 2 jccir ( 𝜑 → ( 𝜓𝜒 ) )
4 3 ancomd ( 𝜑 → ( 𝜒𝜓 ) )