Metamath Proof Explorer


Theorem scottss

Description: Scott's trick produces a subset of the input class. (Contributed by Rohan Ridenour, 11-Aug-2023)

Ref Expression
Assertion scottss Scott 𝐴 ⊆ 𝐴

Proof

Step Hyp Ref Expression
1 df-scott ⊢ Scott 𝐴 = { 𝑥 ∈ 𝐴 ∣ ∀ 𝑦 ∈ 𝐴 ( rank ‘ 𝑥 ) ⊆ ( rank ‘ 𝑦 ) }
2 1 ssrab3 ⊢ Scott 𝐴 ⊆ 𝐴