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Theorem or4 761

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 756	. . 3 $\/$ $\/$ $\/$ $\/$
2	1	orbi2i 752	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
3		orass 757	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
4		orass 757	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
5	2, 3, 4	3bitr4i 211	1 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$

Colors of variables: wff set class

Syntax hints:

wb 104 $\/$ wo 698

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 699

This theorem depends on definitions: df-bi 116

This theorem is referenced by: or42 762 orordi 763 orordir 764 3or6 1313 swoer 6529 apcotr 8505