On simple generators of recursively enumerable languages ?
Polynomial generators for recursively enumerable languages. The languages REP={(amb)n|m,n?N} REP = { ( a m b ) n | m , n ? N } and BREP={(anb)n|n?N} BREP = { ( a n b ) n | n ? N } possess a catenation closure property. Applying classical number theory results in formal languages.
intersection-closed trio r.e. language diophantine equation