Metamath Proof Explorer


Theorem wl-impchain-com-1.3

Description: This theorem is in fact a copy of com13 , and repeated here to demonstrate a simple proof scheme. The number '3' in the theorem name indicates that a chain of length 3 is modified.

See wl-impchain-com-1.x for more information how this proof is generated. (Contributed by Wolf Lammen, 7-Jul-2019) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypothesis wl-impchain-com-1.3.h1 ( 𝜃 → ( 𝜒 → ( 𝜓𝜑 ) ) )
Assertion wl-impchain-com-1.3 ( 𝜓 → ( 𝜒 → ( 𝜃𝜑 ) ) )

Proof

Step Hyp Ref Expression
1 wl-impchain-com-1.3.h1 ( 𝜃 → ( 𝜒 → ( 𝜓𝜑 ) ) )
2 1 wl-impchain-com-1.2 ( 𝜒 → ( 𝜃 → ( 𝜓𝜑 ) ) )
3 wl-luk-pm2.04 ( ( 𝜃 → ( 𝜓𝜑 ) ) → ( 𝜓 → ( 𝜃𝜑 ) ) )
4 2 3 wl-impchain-mp-1 ( 𝜒 → ( 𝜓 → ( 𝜃𝜑 ) ) )
5 4 wl-impchain-com-1.2 ( 𝜓 → ( 𝜒 → ( 𝜃𝜑 ) ) )