Bernhard Gramlich

Learn More
Modular properties of term rewriting systems, i.e. properties which are preserved under disjoint unions, have attracted an increasing attention within the last few years. Whereas confluence is modular this does not hold true in general for termination. By means of a careful analysis of potential counterexamples we prove the following abstract result.(More)
We present a new approach for proving termination of rewrite systems by innermost termination. From the resulting abstract criterion we derive concrete conditions, based on critical peak properties, under which innermost termination implies termination (and connuence). Finally , we show how to apply the main results for providing new suucient conditions for(More)
Term rewriting systems play an important role in various areas, e.g. in abstract data type speciications, for automated theorem proving and as a basic computation model for functional programming languages. In theory and practice, one of the most important properties of term rewriting systems is the strong normalization or ((nite or uniform) termination(More)
In functional languages such as OBJ*, CafeOBJ, and Maude, symbols are given strategy annotations which specify (the order in) which subterms are evaluated. Syntactically, they are given either as lists of natural numbers or as lists of integers associated to function symbols whose (absolute) values refer to the arguments of the corresponding symbol. A(More)
The automated analysis of termination of term rewriting systems (TRSs) has drawn a lot of attention in the scientific community during the last decades and many different methods and approaches have been developed for this purpose. We present VMTL (Vienna Modular Termination Laboratory), a tool implementing some of the most recent and powerful algorithms(More)
For a complete, i.e., connuent and terminating term rewriting system (TRS) it is well-known that simpliication (also called interreduction) into an equivalent canonical, i.e., complete and interreduced TRS is easily possible. This can be achieved by rst normalizing all right-hand sides of the TRS and then deleting all rules with a reducible left-hand side.(More)
We investigate the practically crucial property of operational termination of deterministic conditional term rewriting systems (DCTRSs), an important declarative programming paradigm. We show that operational termination can be equivalently characterized by the newly introduced notion of context-sensitive quasi-reductivity. Based on this characterization(More)