Theorem impt 157

Description: Importation theorem expressed with primitive connectives. (Contributed by NM, 25-Apr-1994.) (Proof shortened by Wolf Lammen, 20-Jul-2013.)

Assertion

Ref	Expression
impt

Proof of Theorem impt

Step	Hyp	Ref	Expression
1		simprim 150	. 2
2		simplim 151	. . 3
3	2	imim1i 58	. 2
4	1, 3	mpdi 42	1

Syntax hints:  -.wn 3  ->wi 4

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8