Theorem inss1

Description: The intersection of two classes is a subset of one of them. Part of Exercise 12 of TakeutiZaring p. 18. (Contributed by NM, 27-Apr-1994)

	Ref	Expression
Assertion	inss1	$$⊢A\cap B\subseteq A$$

Proof

Step	Hyp	Ref	Expression
1		elinel1	$$⊢x\in \left(A\cap B\right)\to x\in A$$
2	1	ssriv	$$⊢A\cap B\subseteq A$$