/export/starexec/sandbox2/solver/bin/starexec_run_default /export/starexec/sandbox2/benchmark/theBenchmark.xml /export/starexec/sandbox2/output/output_files -------------------------------------------------------------------------------- NO ** BEGIN proof argument ** The following rule was generated while unfolding the analyzed TRS: [iteration = 3] f(_0,h(h(_1))) -> f(h(h(f(f(h(a),a),f(h(a),_1)))),_0) Let l be the left-hand side and r be the right-hand side of this rule. Let p = epsilon, theta1 = {_0->h(h(_2))} and theta2 = {_1->_2, _2->f(f(h(a),a),f(h(a),_1))}. We have r|p = f(h(h(f(f(h(a),a),f(h(a),_1)))),_0) and theta2(theta1(l)) = theta1(r|p). Hence, the term theta1(l) = f(h(h(_2)),h(h(_1))) loops w.r.t. the analyzed TRS. ** END proof argument ** ** BEGIN proof description ** ## Searching for a generalized rewrite rule (a rule whose right-hand side contains a variable that does not occur in the left-hand side)... No generalized rewrite rule found! ## Applying the DP framework... ## 1 initial DP problem to solve. ## First, we try to decompose this problem into smaller problems. ## Round 1 [1 DP problem]: ## DP problem: Dependency pairs = [f^#(_0,h(_1)) -> f^#(f(h(a),_1),_0), f^#(_0,h(_1)) -> f^#(h(a),_1)] TRS = {f(_0,h(_1)) -> h(f(f(h(a),_1),_0))} ## Trying with homeomorphic embeddings... Failed! ## Trying with polynomial interpretations... Failed! ## Trying with lexicographic path orders... Failed! ## Trying with Knuth-Bendix orders... Failed! Don't know whether this DP problem is finite. ## A DP problem could not be proved finite. ## Now, we try to prove that this problem is infinite. ## Trying to find a loop (forward=true, backward=true, max=20) # max_depth=20, unfold_variables=false: # Iteration 0: no loop found, 2 unfolded rules generated. # Iteration 1: no loop found, 5 unfolded rules generated. # Iteration 2: no loop found, 8 unfolded rules generated. # Iteration 3: success, found a loop, 1 unfolded rule generated. Here is the successful unfolding. Let IR be the TRS under analysis. L0 = f^#(_0,h(_1)) -> f^#(f(h(a),_1),_0) [trans] is in U_IR^0. D = f^#(_0,h(_1)) -> f^#(h(a),_1) is a dependency pair of IR. We build a composed triple from L0 and D. ==> L1 = [f^#(_0,h(_1)) -> f^#(f(h(a),_1),_0), f^#(_2,h(_3)) -> f^#(h(a),_3)] [comp] is in U_IR^1. Let p1 = [0]. We unfold the first rule of L1 forwards at position p1 with the rule f(_0,h(_1)) -> h(f(f(h(a),_1),_0)). ==> L2 = [f^#(_0,h(h(_1))) -> f^#(h(f(f(h(a),_1),h(a))),_0), f^#(_2,h(_3)) -> f^#(h(a),_3)] [comp] is in U_IR^2. Let p2 = [0, 0]. We unfold the first rule of L2 forwards at position p2 with the rule f(_0,h(_1)) -> h(f(f(h(a),_1),_0)). ==> L3 = [f^#(_0,h(h(_1))) -> f^#(h(h(f(f(h(a),a),f(h(a),_1)))),_0), f^#(_2,h(_3)) -> f^#(h(a),_3)] [comp] is in U_IR^3. This DP problem is infinite. Proof run on Linux version 3.10.0-1160.25.1.el7.x86_64 for amd64 using Java version 1.8.0_292 ** END proof description ** Total number of generated unfolded rules = 61