Theorem orass 75

Description: Associative law.

Assertion

Ref	Expression
orass	((a ∪ b) ∪ c) = (a ∪ (b ∪ c))

Proof of Theorem orass

Step	Hyp	Ref	Expression
1		ax-a3 32	1 ((a ∪ b) ∪ c) = (a ∪ (b ∪ c))

Syntax hints:   = wb 1   ∪ wo 6

This theorem was proved from axioms:  ax-a3 32

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