Metamath Proof Explorer


Theorem rabssdv

Description: Subclass of a restricted class abstraction (deduction form). (Contributed by NM, 2-Feb-2015)

Ref Expression
Hypothesis rabssdv.1 ( ( 𝜑𝑥𝐴𝜓 ) → 𝑥𝐵 )
Assertion rabssdv ( 𝜑 → { 𝑥𝐴𝜓 } ⊆ 𝐵 )

Proof

Step Hyp Ref Expression
1 rabssdv.1 ( ( 𝜑𝑥𝐴𝜓 ) → 𝑥𝐵 )
2 1 3exp ( 𝜑 → ( 𝑥𝐴 → ( 𝜓𝑥𝐵 ) ) )
3 2 ralrimiv ( 𝜑 → ∀ 𝑥𝐴 ( 𝜓𝑥𝐵 ) )
4 rabss ( { 𝑥𝐴𝜓 } ⊆ 𝐵 ↔ ∀ 𝑥𝐴 ( 𝜓𝑥𝐵 ) )
5 3 4 sylibr ( 𝜑 → { 𝑥𝐴𝜓 } ⊆ 𝐵 )