Description: An element of the powerset of B intersected with anything, is a subset of B . (Contributed by Glauco Siliprandi, 17-Aug-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | elpwinss | ⊢ ( 𝐴 ∈ ( 𝒫 𝐵 ∩ 𝐶 ) → 𝐴 ⊆ 𝐵 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elinel1 | ⊢ ( 𝐴 ∈ ( 𝒫 𝐵 ∩ 𝐶 ) → 𝐴 ∈ 𝒫 𝐵 ) | |
2 | 1 | elpwid | ⊢ ( 𝐴 ∈ ( 𝒫 𝐵 ∩ 𝐶 ) → 𝐴 ⊆ 𝐵 ) |