![[MONOiD]](monoid.png)
PartialOrderDClasses( M )
The inclusion order on the set of the two sided principal ideals of the
monoid M induces a natural order on the D classes of M.
PartialOrderDClasses returns this partial order of the D classes of the
monoid M as a binary relation.
gap> M:= Monoid( Transformation( [ 2, 1, 2 ] ),
> Transformation( [ 1, 2, 2 ] ) );;
gap> PartialOrderDClasses(M);
Relation( [ [ 1, 2 ], [ 2 ] ] )
The function HasseDiagram (see HasseDiagram) can be used to convert
this binary relation into a smaller one that implies the same partial
order.