or42 - Intuitionistic Logic Explorer

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Theorem or42 721

Description: Rearrangement of 4 disjuncts. (Contributed by NM, 10-Jan-2005.)

**Assertion**
Ref	Expression
or42	$\/$ $\/$ $\/$ $\/$ $\/$ $\/$

**Proof of Theorem or42**
Step	Hyp	Ref	Expression
1		or4 720	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
2		orcom 679	. . 3 $\/$ $\/$
3	2	orbi2i 711	. 2 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$
4	1, 3	bitri 182	1 $\/$ $\/$ $\/$ $\/$ $\/$ $\/$

Colors of variables: wff set class

Syntax hints:

wb 103 $\/$ wo 661

This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 662

This theorem depends on definitions: df-bi 115

This theorem is referenced by: reapcotr 7698