Prelanguages versus submonoids
In [9] submonoids of a commutative monoid are characterized by means of their relations of domination, subgroups of a commutative monoid are characterized by means of their relations of double domination. The main purpose of this paper is to transfer these results to general monoids. The important means will be certain relations, which we shall study in detail.
prelanguage submonoid monoid pregrammar relation of left domination of a prelanguage relation of left double domination of a prelanguage