Confluence of Length Preserving String Rewriting Systems is Undecidable
نویسندگان
چکیده
Confluence that ensures the uniqueness of results of computation is one of important properties on rewriting systems. In this paper, we show undecidability of confluence for length preserving string rewriting systems (SRSs) and prove it by reducing the Post’s correspondence problem (PCP), which is known to be undecidable, to confluence problem of length preserving string rewriting systems. More precisely, we designed a reduction algorithm having the property that the existence of a solution for a given instance of PCP coincides with the non-confluence of the SRS obtained from the reduction algorithm.
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