Theorem prlem2 963

Description: A specialized lemma for set theory (to derive the Axiom of Pairing). (Contributed by NM, 21-Jun-1993.) (Proof shortened by Andrew Salmon, 13-May-2011.) (Proof shortened by Wolf Lammen, 9-Dec-2012.)

Assertion

Ref	Expression
prlem2

Proof of Theorem prlem2

Step	Hyp	Ref	Expression
1		simpl 457	. . 3
2		simpl 457	. . 3
3	1, 2	orim12i 516	. 2
4	3	pm4.71ri 633	1

Syntax hints:  <->wb 184  \/wo 368  /\wa 369

This theorem is referenced by:  zfpair  4689

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 185  df-or 370  df-an 371