rb-ax2 - Metamath Proof Explorer

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Theorem rb-ax2 1678

Description: The second of four axioms in the Russell-Bernays axiom system. (Contributed by Anthony Hart, 13-Aug-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

**Assertion**
Ref	Expression
rb-ax2	$\/$ $\/$ $\/$

**Proof of Theorem rb-ax2**
Step	Hyp	Ref	Expression
1		pm1.4 401	. . . 4 $\/$ $\/$
2	1	con3i 150	. . 3 $\/$ $\/$
3	2	con1i 144	. 2 $\/$ $\/$
4	3	orri 391	1 $\/$ $\/$ $\/$

Colors of variables: wff setvar class

Syntax hints:

wn 3 $\/$ 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: rblem1 1682 rblem2 1683 rblem3 1684 rblem4 1685 rblem5 1686 rblem6 1687 re2luk1 1690 re2luk2 1691 re2luk3 1692

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