or4 - Intuitionistic Logic Explorer

	Intuitionistic Logic Explorer		< Previous Next > Nearby theorems
Mirrors > Home > ILE Home > Th. List > or4		Unicode version

Theorem or4 772

Description: Rearrangement of 4 disjuncts. (Contributed by NM, 12-Aug-1994.)

**Assertion**
Ref	Expression
or4	$\/$ $\/$ $\/$ $\/$ $\/$ $\/$

**Proof of Theorem or4**
Step	Hyp	Ref	Expression
1		or12 767	. . 3 $\/$ $\/$ $\/$ $\/$
2	1	orbi2i 763	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
3		orass 768	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
4		orass 768	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
5	2, 3, 4	3bitr4i 212	1 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$

Colors of variables: wff set class

Syntax hints:

wb 105 $\/$ wo 709

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 710

This theorem depends on definitions: df-bi 117

This theorem is referenced by: or42 773 orordi 774 orordir 775 3or6 1334 swoer 6629 apcotr 8651