Metamath Proof Explorer
Description: The converse of the non-relation part of a class is empty. (Contributed by RP, 18-Oct-2020)
|
|
Ref |
Expression |
|
Assertion |
cnvnonrel |
⊢ ◡ ( 𝐴 ∖ ◡ ◡ 𝐴 ) = ∅ |
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
cnvdif |
⊢ ◡ ( 𝐴 ∖ ◡ ◡ 𝐴 ) = ( ◡ 𝐴 ∖ ◡ ◡ ◡ 𝐴 ) |
| 2 |
|
relcnv |
⊢ Rel ◡ 𝐴 |
| 3 |
|
relnonrel |
⊢ ( Rel ◡ 𝐴 ↔ ( ◡ 𝐴 ∖ ◡ ◡ ◡ 𝐴 ) = ∅ ) |
| 4 |
2 3
|
mpbi |
⊢ ( ◡ 𝐴 ∖ ◡ ◡ ◡ 𝐴 ) = ∅ |
| 5 |
1 4
|
eqtri |
⊢ ◡ ( 𝐴 ∖ ◡ ◡ 𝐴 ) = ∅ |