/export/starexec/sandbox/solver/bin/starexec_run_default /export/starexec/sandbox/benchmark/theBenchmark.xml /export/starexec/sandbox/output/output_files -------------------------------------------------------------------------------- NO ** BEGIN proof argument ** The following rule was generated while unfolding the analyzed TRS: [iteration = 6] f(b,b) -> f(b,b) Let l be the left-hand side and r be the right-hand side of this rule. Let p = epsilon, theta1 = {} and theta2 = {}. We have r|p = f(b,b) and theta2(theta1(l)) = theta1(r|p). Hence, the term theta1(l) = f(b,b) 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 = [h^#(_0) -> g^#(_0,_0), f^#(_0,_0) -> h^#(a), g^#(a,_0) -> f^#(b,activate(_0))] TRS = {h(_0) -> g(_0,_0), g(a,_0) -> f(b,activate(_0)), f(_0,_0) -> h(a), a -> b, activate(_0) -> _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=false, max=-1) # max_depth=2, unfold_variables=false: # Iteration 0: no loop found, 3 unfolded rules generated. # Iteration 1: no loop found, 5 unfolded rules generated. # Iteration 2: no loop found, 7 unfolded rules generated. # Iteration 3: no loop found, 9 unfolded rules generated. # Iteration 4: no loop found, 1 unfolded rule generated. # Iteration 5: no loop found, 2 unfolded rules generated. # Iteration 6: success, found a loop, 1 unfolded rule generated. Here is the successful unfolding. Let IR be the TRS under analysis. L0 = f^#(_0,_0) -> h^#(a) [trans] is in U_IR^0. D = h^#(_0) -> g^#(_0,_0) is a dependency pair of IR. We build a composed triple from L0 and D. ==> L1 = f^#(_0,_0) -> g^#(a,a) [trans] is in U_IR^1. D = g^#(a,_0) -> f^#(b,activate(_0)) is a dependency pair of IR. We build a composed triple from L1 and D. ==> L2 = f^#(_0,_0) -> f^#(b,activate(a)) [trans] is in U_IR^2. We build a unit triple from L2. ==> L3 = f^#(_0,_0) -> f^#(b,activate(a)) [unit] is in U_IR^3. Let p3 = [0]. The subterm at position p3 in the left-hand side of the rule of L3 unifies with the subterm at position p3 in the right-hand side of the rule of L3. ==> L4 = f^#(b,b) -> f^#(b,activate(a)) [unit] is in U_IR^4. Let p4 = [1]. We unfold the rule of L4 forwards at position p4 with the rule activate(_0) -> _0. ==> L5 = f^#(b,b) -> f^#(b,a) [unit] is in U_IR^5. Let p5 = [1]. We unfold the rule of L5 forwards at position p5 with the rule a -> b. ==> L6 = f^#(b,b) -> f^#(b,b) [unit] is in U_IR^6. 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 = 118