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Description: Subclass relation for a restricted class. (Contributed by Glauco Siliprandi, 26-Jun-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | ssrab2f.1 | ⊢ Ⅎ 𝑥 𝐴 | |
| Assertion | ssrab2f | ⊢ { 𝑥 ∈ 𝐴 ∣ 𝜑 } ⊆ 𝐴 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ssrab2f.1 | ⊢ Ⅎ 𝑥 𝐴 | |
| 2 | nfrab1 | ⊢ Ⅎ 𝑥 { 𝑥 ∈ 𝐴 ∣ 𝜑 } | |
| 3 | 2 1 | dfss3f | ⊢ ( { 𝑥 ∈ 𝐴 ∣ 𝜑 } ⊆ 𝐴 ↔ ∀ 𝑥 ∈ { 𝑥 ∈ 𝐴 ∣ 𝜑 } 𝑥 ∈ 𝐴 ) |
| 4 | rabidim1 | ⊢ ( 𝑥 ∈ { 𝑥 ∈ 𝐴 ∣ 𝜑 } → 𝑥 ∈ 𝐴 ) | |
| 5 | 3 4 | mprgbir | ⊢ { 𝑥 ∈ 𝐴 ∣ 𝜑 } ⊆ 𝐴 |