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Theorem con4bii 288

Description: A contraposition inference. (Contributed by NM, 21-May-1994.)

Hypothesis

Ref	Expression
con4bii.1

Assertion

Ref	Expression
con4bii

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Proof of Theorem con4bii

Step	Hyp	Ref	Expression
1		con4bii.1	. 2
2		notbi 286	. 2
3	1, 2	mpbir 200	1

Colors of variables: wff setvar class

Syntax hints:   wn 3   wb 176

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

This theorem depends on definitions:  df-bi 177

This theorem is referenced by:  2false  339  19.35  1600  2ralor  2780  gencbval  2903  eq0  3564  ab0  3569  uni0b  3916

Copyright terms: Public domain

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