Description: The converse of the trivial closure is equal to the closure of the converse. (Contributed by RP, 18-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cnvtrucl0 | ⊢ ( 𝑋 ∈ 𝑉 → ◡ ∩ { 𝑥 ∣ ( 𝑋 ⊆ 𝑥 ∧ ⊤ ) } = ∩ { 𝑦 ∣ ( ◡ 𝑋 ⊆ 𝑦 ∧ ⊤ ) } ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | idd | ⊢ ( ( 𝑋 ∈ 𝑉 ∧ 𝑥 = ( ◡ 𝑦 ∪ ( 𝑋 ∖ ◡ ◡ 𝑋 ) ) ) → ( ⊤ → ⊤ ) ) | |
| 2 | idd | ⊢ ( ( 𝑋 ∈ 𝑉 ∧ 𝑦 = ◡ 𝑥 ) → ( ⊤ → ⊤ ) ) | |
| 3 | biidd | ⊢ ( 𝑥 = 𝑋 → ( ⊤ ↔ ⊤ ) ) | |
| 4 | ssidd | ⊢ ( 𝑋 ∈ 𝑉 → 𝑋 ⊆ 𝑋 ) | |
| 5 | elex | ⊢ ( 𝑋 ∈ 𝑉 → 𝑋 ∈ V ) | |
| 6 | trud | ⊢ ( 𝑋 ∈ 𝑉 → ⊤ ) | |
| 7 | 1 2 3 4 5 6 | clcnvlem | ⊢ ( 𝑋 ∈ 𝑉 → ◡ ∩ { 𝑥 ∣ ( 𝑋 ⊆ 𝑥 ∧ ⊤ ) } = ∩ { 𝑦 ∣ ( ◡ 𝑋 ⊆ 𝑦 ∧ ⊤ ) } ) |