Theorem chub2i

Description: CH join is an upper bound of two elements. (Contributed by NM, 5-Nov-2000) (New usage is discouraged.)

	Ref	Expression
Hypotheses	ch0le.1	|- A e. CH
	chjcl.2	|- B e. CH
Assertion	chub2i	|- A C_ ( B vH A )

Proof

Step	Hyp	Ref	Expression
1		ch0le.1	|- A e. CH
2		chjcl.2	|- B e. CH
3	1 2	chub1i	|- A C_ ( A vH B )
4	1 2	chjcomi	|- ( A vH B ) = ( B vH A )
5	3 4	sseqtri	|- A C_ ( B vH A )