This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Membership in a power class. (Contributed by Glauco Siliprandi, 11-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | elpwd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| elpwd.2 | ⊢ ( 𝜑 → 𝐴 ⊆ 𝐵 ) | ||
| Assertion | elpwd | ⊢ ( 𝜑 → 𝐴 ∈ 𝒫 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elpwd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| 2 | elpwd.2 | ⊢ ( 𝜑 → 𝐴 ⊆ 𝐵 ) | |
| 3 | elpwg | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 ∈ 𝒫 𝐵 ↔ 𝐴 ⊆ 𝐵 ) ) | |
| 4 | 1 3 | syl | ⊢ ( 𝜑 → ( 𝐴 ∈ 𝒫 𝐵 ↔ 𝐴 ⊆ 𝐵 ) ) |
| 5 | 2 4 | mpbird | ⊢ ( 𝜑 → 𝐴 ∈ 𝒫 𝐵 ) |