“…In fact, confluence provers for CTRSs, ConCon [28], CO3 [20], and CoScart [9], based on e.g., transformations of CTRSs into TRSs or reachability analysis for infeasibility of conditional critical pairs, failed to prove confluence of R 1 (see Confluence Competition 2016, 2017, and 2018, 1 327.trs). In addition, a semantic approach in [16,15] cannot prove confluence of R 1 using AGES [12], a tool for generating logical models of order-sorted first-order theories-non-existence of t 1 ,t 2 above cannot be proved via its web interface with default parameters. Timbuk 3.2 [7], which is based on tree automata techniques [6], cannot prove infeasibility of x < y true, y < x true w.r.t.…”