Description: Lemma for currysetALT . (Contributed by BJ, 23-Sep-2023) This proof is intuitionistically valid. (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | currysetlem2.def | ⊢ 𝑋 = { 𝑥 ∣ ( 𝑥 ∈ 𝑥 → 𝜑 ) } | |
| Assertion | currysetlem2 | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝑋 ∈ 𝑋 → 𝜑 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | currysetlem2.def | ⊢ 𝑋 = { 𝑥 ∣ ( 𝑥 ∈ 𝑥 → 𝜑 ) } | |
| 2 | 1 | currysetlem1 | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝑋 ∈ 𝑋 ↔ ( 𝑋 ∈ 𝑋 → 𝜑 ) ) ) | 
| 3 | 2 | biimpd | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝑋 ∈ 𝑋 → ( 𝑋 ∈ 𝑋 → 𝜑 ) ) ) | 
| 4 | 3 | pm2.43d | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝑋 ∈ 𝑋 → 𝜑 ) ) |