Theorem ssel2

Description: Membership relationships follow from a subclass relationship. (Contributed by NM, 7-Jun-2004)

	Ref	Expression
Assertion	ssel2	$$⊢\left(A\subseteq B\wedge C\in A\right)\to C\in B$$

Proof

Step	Hyp	Ref	Expression
1		ssel	$$⊢A\subseteq B\to \left(C\in A\to C\in B\right)$$
2	1	imp	$$⊢\left(A\subseteq B\wedge C\in A\right)\to C\in B$$