Metamath Proof Explorer


Theorem elscottn0

Description: If the input class has elements, then the Scott's trick set is not empty. (Contributed by BTernaryTau, 23-Aug-2026)

Ref Expression
Assertion elscottn0 ( 𝐴 ∈ 𝐵 → Scott 𝐵 ≠ ∅ )

Proof

Step Hyp Ref Expression
1 ne0i ⊢ ( 𝐴 ∈ 𝐵 → 𝐵 ≠ ∅ )
2 scott0b ⊢ ( 𝐵 = ∅ ↔ Scott 𝐵 = ∅ )
3 2 necon3bii ⊢ ( 𝐵 ≠ ∅ ↔ Scott 𝐵 ≠ ∅ )
4 1 3 sylib ⊢ ( 𝐴 ∈ 𝐵 → Scott 𝐵 ≠ ∅ )