Abstract:
The following problem was soluted.Which languages are the producte of left cancellative languages and the disjunctive languages or its generalizations First,the following important result was proved:If X is a left cancellative language and Y is a language,then PXY⊆PY.Then,based on it,the following properties on disjunctive language and its generalization were obtained:If X is a left cancellative language and Y is a disjunctive language or its generalization,then XY is a disjunctive language or its generalization.