Metamath Proof Explorer


Theorem sseli

Description: Membership implication from subclass relationship. (Contributed by NM, 5-Aug-1993)

Ref Expression
Hypothesis sseli.1 𝐴𝐵
Assertion sseli ( 𝐶𝐴𝐶𝐵 )

Proof

Step Hyp Ref Expression
1 sseli.1 𝐴𝐵
2 ssel ( 𝐴𝐵 → ( 𝐶𝐴𝐶𝐵 ) )
3 1 2 ax-mp ( 𝐶𝐴𝐶𝐵 )