Theorem chm1i

Description: Meet with lattice one in CH . (Contributed by NM, 24-Oct-1999) (New usage is discouraged.)

	Ref	Expression
Hypothesis	ch0le.1	|- A e. CH
Assertion	chm1i	|- ( A i^i ~H ) = A

Proof

Step	Hyp	Ref	Expression
1		ch0le.1	|- A e. CH
2	1	chssii	|- A C_ ~H
3		dfss2	|- ( A C_ ~H <-> ( A i^i ~H ) = A )
4	2 3	mpbi	|- ( A i^i ~H ) = A