Metamath Proof Explorer


Theorem ssrab2

Description: Subclass relation for a restricted class. (Contributed by NM, 19-Mar-1997)

Ref Expression
Assertion ssrab2 { 𝑥𝐴𝜑 } ⊆ 𝐴

Proof

Step Hyp Ref Expression
1 df-rab { 𝑥𝐴𝜑 } = { 𝑥 ∣ ( 𝑥𝐴𝜑 ) }
2 ssab2 { 𝑥 ∣ ( 𝑥𝐴𝜑 ) } ⊆ 𝐴
3 1 2 eqsstri { 𝑥𝐴𝜑 } ⊆ 𝐴