文摘
We define a class of languages (RCMRCM) obtained by considering Regular languages, linear Constraints on the number of occurrences of symbols and Morphisms. The class RCMRCM presents some interesting closure properties, and contains languages with holonomic generating functions. As a matter of fact, RCMRCM is related to one-way 1-reversal bounded k -counter machines and also to Parikh automata on letters. Indeed, RCMRCM is contained in LNFCMLNFCM but not in LDFCMLDFCM, and strictly includes LLPALLPA. We conjecture that LDFCM⊂RCMLDFCM⊂RCM.