Metamath Proof Explorer


Theorem bj-cnvresrn

Description: Duplicate of cnvresrn , to be moved to the main section. The converse restricted to the range is equal to the converse. Analogue of resdmb since a converse is always a relation ( relcnv ). (Contributed by Peter Mazsa, 3-Sep-2021) Can shorten domss2 .

Ref Expression
Assertion bj-cnvresrn
|- ( `' R |` ran R ) = `' R

Proof

Step Hyp Ref Expression
1 df-rn
 |-  ran R = dom `' R
2 1 reseq2i
 |-  ( `' R |` ran R ) = ( `' R |` dom `' R )
3 relcnv
 |-  Rel `' R
4 resdmb
 |-  ( Rel `' R <-> ( `' R |` dom `' R ) = `' R )
5 3 4 mpbi
 |-  ( `' R |` dom `' R ) = `' R
6 2 5 eqtri
 |-  ( `' R |` ran R ) = `' R