![[MONOiD]](monoid.png)
IsPreOrder( rel )
IsPreOrder returns true if the binary relation rel is a preoder and
false otherwise.
gap> IsPreOrder( Relation( [ [ ], [ 1 ], [ 1, 2 ] ] ) );
false
gap> IsPreOrder( Relation( [ [ 1, 2 ], [ 1, 2 ], [ 1, 2, 3 ] ] ) );
true
A relation rel is called a preorder if rel is reflexive and
transitive.
Version 2.4 (May 1998)