Theorem or1r 97

Description: Disjunction with 1.

Assertion

Ref	Expression
or1r	(1 ∪ a) = 1

Proof of Theorem or1r

Step	Hyp	Ref	Expression
1		ax-a2 30	. 2 (1 ∪ a) = (a ∪ 1)
2		or1 96	. 2 (a ∪ 1) = 1
3	1, 2	ax-r2 35	1 (1 ∪ a) = 1

Syntax hints:   = wb 1   ∪ wo 6  1wt 9

This theorem is referenced by:  ud3lem1c 550  ud3lem3 558  ud5lem1 571  i1orni1 829

This theorem was proved from axioms:  ax-a2 30  ax-a4 32  ax-r1 34  ax-r2 35  ax-r5 37

This theorem depends on definitions:  df-t 40

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