Metamath Proof Explorer


Theorem cnvtrucl0

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 ( 𝑋𝑉 { 𝑥 ∣ ( 𝑋𝑥 ∧ ⊤ ) } = { 𝑦 ∣ ( 𝑋𝑦 ∧ ⊤ ) } )

Proof

Step Hyp Ref Expression
1 idd ( ( 𝑋𝑉𝑥 = ( 𝑦 ∪ ( 𝑋 𝑋 ) ) ) → ( ⊤ → ⊤ ) )
2 idd ( ( 𝑋𝑉𝑦 = 𝑥 ) → ( ⊤ → ⊤ ) )
3 biidd ( 𝑥 = 𝑋 → ( ⊤ ↔ ⊤ ) )
4 ssidd ( 𝑋𝑉𝑋𝑋 )
5 elex ( 𝑋𝑉𝑋 ∈ V )
6 trud ( 𝑋𝑉 → ⊤ )
7 1 2 3 4 5 6 clcnvlem ( 𝑋𝑉 { 𝑥 ∣ ( 𝑋𝑥 ∧ ⊤ ) } = { 𝑦 ∣ ( 𝑋𝑦 ∧ ⊤ ) } )