Metamath Proof Explorer


Theorem trgtmd

Description: The multiplicative monoid of a topological ring is a topological monoid. (Contributed by Mario Carneiro, 5-Oct-2015)

Ref Expression
Hypothesis istrg.1
|- M = ( mulGrp ` R )
Assertion trgtmd
|- ( R e. TopRing -> M e. TopMnd )

Proof

Step Hyp Ref Expression
1 istrg.1
 |-  M = ( mulGrp ` R )
2 1 istrg
 |-  ( R e. TopRing <-> ( R e. TopGrp /\ R e. Ring /\ M e. TopMnd ) )
3 2 simp3bi
 |-  ( R e. TopRing -> M e. TopMnd )