Metamath Proof Explorer


Theorem elelpwi

Description: If A belongs to a part of C , then A belongs to C . (Contributed by FL, 3-Aug-2009)

Ref Expression
Assertion elelpwi ⊢ A ∈ B ∧ B ∈ 𝒫 C → A ∈ C

Proof

Step Hyp Ref Expression
1 elpwi ⊢ B ∈ 𝒫 C → B ⊆ C
2 1 sseld ⊢ B ∈ 𝒫 C → A ∈ B → A ∈ C
3 2 impcom ⊢ A ∈ B ∧ B ∈ 𝒫 C → A ∈ C