biortn - Metamath Proof Explorer

	Metamath Proof Explorer		< Previous Next > Nearby theorems
Mirrors > Home > MPE Home > Th. List > biortn		Structured version Visualization version Unicode version

Theorem biortn 421

Description: A wff is equivalent to its negated disjunction with falsehood. (Contributed by NM, 9-Jul-2012.)

**Assertion**
Ref	Expression
biortn	$\/$

**Proof of Theorem biortn**
Step	Hyp	Ref	Expression
1		notnot 136	. 2
2		biorf 420	. 2 $\/$
3	1, 2	syl 17	1 $\/$

Colors of variables: wff setvar class

Syntax hints:

wn 3

wi 4

wb 196 $\/$ wo 383

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

This theorem depends on definitions: df-bi 197 df-or 385

This theorem is referenced by: oranabs 901 xrdifh 29542 ballotlemfc0 30554 ballotlemfcc 30555 topdifinfindis 33194 topdifinffinlem 33195 4atlem3a 34883 4atlem3b 34884 ntrneineine1lem 38382