Metamath Proof Explorer


Theorem cossssid

Description: Equivalent expressions for the class of cosets by R to be a subset of the identity class. (Contributed by Peter Mazsa, 27-Jul-2021)

Ref Expression
Assertion cossssid RIRIdomR×ranR

Proof

Step Hyp Ref Expression
1 iss2 RIR=IdomR×ranR
2 refrelcoss2 IdomR×ranRRRelR
3 2 simpli IdomR×ranRR
4 eqss R=IdomR×ranRRIdomR×ranRIdomR×ranRR
5 3 4 mpbiran2 R=IdomR×ranRRIdomR×ranR
6 1 5 bitri RIRIdomR×ranR