1.26 Idempotents

Idempotents( M )
Idempotents( class )

returns the set of idempotents in the monoid M or in a Green class class.

    gap> M:= Monoid( Transformation( [ 2, 1, 2 ] ),
    > Transformation( [ 1, 2, 2 ] ) );;
    gap> Idempotents( M );
    [ Transformation( [ 1, 2, 1 ] ), Transformation( [ 1, 2, 2 ] ), 
      Transformation( [ 1, 2, 3 ] ) ] 
    gap> Idempotents( DClass( M, Transformation( [ 2, 1, 2 ] ) ) );
    [ Transformation( [ 1, 2, 1 ] ), Transformation( [ 1, 2, 2 ] ) ] 

   
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