Metamath Proof Explorer


Theorem impcom

Description: Importation inference with commuted antecedents. (Contributed by NM, 25-May-2005)

Ref Expression
Hypothesis imp.1 φψχ
Assertion impcom ψφχ

Proof

Step Hyp Ref Expression
1 imp.1 φψχ
2 1 com12 ψφχ
3 2 imp ψφχ