Metamath Proof Explorer


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 B

Proof

Step Hyp Ref Expression
1 atombase.b B = Base K
2 atombase.a A = Atoms K
3 1 2 atbase x A x B
4 3 ssriv A B