Theorem atssbase

Description: The set of atoms is a subset of the base set. ( atssch analog.) (Contributed by NM, 21-Oct-2011)

	Ref	Expression
Hypotheses	atombase.b	|- B = ( Base ` K )
	atombase.a	|- A = ( Atoms ` K )
Assertion	atssbase	|- A C_ B

Proof

Step	Hyp	Ref	Expression
1		atombase.b	|- B = ( Base ` K )
2		atombase.a	|- A = ( Atoms ` K )
3	1 2	atbase	|- ( x e. A -> x e. B )
4	3	ssriv	|- A C_ B