Metamath Proof Explorer


Theorem efmndsgrp

Description: The monoid of endofunctions on a class A is a semigroup. (Contributed by AV, 28-Jan-2024)

Ref Expression
Hypothesis efmndmgm.g No typesetting found for |- G = ( EndoFMnd ` A ) with typecode |-
Assertion efmndsgrp Could not format assertion : No typesetting found for |- G e. Smgrp with typecode |-

Proof

Step Hyp Ref Expression
1 efmndmgm.g Could not format G = ( EndoFMnd ` A ) : No typesetting found for |- G = ( EndoFMnd ` A ) with typecode |-
2 1 efmndmgm G Mgm
3 eqid Base G = Base G
4 eqid + G = + G
5 1 3 4 efmndcl x Base G y Base G x + G y Base G
6 1 3 4 efmndov x Base G y Base G x + G y = x y
7 5 6 symggrplem f Base G g Base G h Base G f + G g + G h = f + G g + G h
8 7 rgen3 f Base G g Base G h Base G f + G g + G h = f + G g + G h
9 3 4 issgrp Could not format ( G e. Smgrp <-> ( G e. Mgm /\ A. f e. ( Base ` G ) A. g e. ( Base ` G ) A. h e. ( Base ` G ) ( ( f ( +g ` G ) g ) ( +g ` G ) h ) = ( f ( +g ` G ) ( g ( +g ` G ) h ) ) ) ) : No typesetting found for |- ( G e. Smgrp <-> ( G e. Mgm /\ A. f e. ( Base ` G ) A. g e. ( Base ` G ) A. h e. ( Base ` G ) ( ( f ( +g ` G ) g ) ( +g ` G ) h ) = ( f ( +g ` G ) ( g ( +g ` G ) h ) ) ) ) with typecode |-
10 2 8 9 mpbir2an Could not format G e. Smgrp : No typesetting found for |- G e. Smgrp with typecode |-