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In this paper we study size properties of context-free returning parallel communicating grammar systems (PC grammar systems). We show that for each context-free returning PC grammar system an equivalent system of this type can be constructed, where the total number of symbols used for describing a component can be bounded by a reasonably small constant. Since context-free returning PC grammar systems determine the class of recursively enumerable languages, the result also demonstrates that thedoi:10.1016/s0304-3975(01)00172-4 fatcat:thyzvycgabgfrp2bks6f76cwse