@article{wirth-shallow-confluence, year ={2008}, author ={Claus-Peter Wirth}, title ={Shallow Confluence of Conditional Term Rewriting Systems}, journal ={J. of Symbolic Computation}, publisher ={Elsevier}, url ={http://dx.doi.org/10.1016/j.jsc.2008.05.005}, abstract ={Recursion can be conveniently modeled with left-linear positive/negative-conditional term rewriting systems, provided that non-termination, non-trivial critical overlaps, non-right-stability, non-normality, and extra variables are admitted. For such systems we present novel sufficient criteria for shallow confluence and arrive at the first decidable confluence criterion admitting non-trivial critical overlaps. To this end, we restrict the introduction of extra variables of right-hand sides to binding equations and require the critical pairs to have somehow complementary literals in their conditions. Shallow confluence implies level confluence, has applications in functional logic programming, and guarantees the object-level consistency of the underlying data types in the inductive theorem prover QUODLIBET.}, }