Metamath Proof Explorer


Theorem wl-luk-com12

Description: Inference that swaps (commutes) antecedents in an implication. Copy of com12 with a different proof. (Contributed by Wolf Lammen, 17-Dec-2018) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypothesis wl-luk-com12.1 φ ψ χ
Assertion wl-luk-com12 ψ φ χ

Proof

Step Hyp Ref Expression
1 wl-luk-com12.1 φ ψ χ
2 wl-luk-pm2.27 ψ ψ χ χ
3 1 2 wl-luk-imtrid ψ φ χ