WORST_CASE(Omega(n^1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l4 0: l0 -> l2 : x^0'=x^post_1, [ x^post_1==-1+x^0 ], cost: 1 1: l2 -> l1 : x^0'=x^post_2, [ 1<=x^0 && x^0==x^post_2 ], cost: 1 2: l2 -> l1 : x^0'=x^post_3, [ 1+x^0<=0 && x^0==x^post_3 ], cost: 1 3: l1 -> l0 : x^0'=x^post_4, [ x^0==x^post_4 ], cost: 1 4: l3 -> l0 : x^0'=x^post_5, [ 1<=x^0 && x^0==x^post_5 ], cost: 1 5: l4 -> l3 : x^0'=x^post_6, [ x^0==x^post_6 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 5: l4 -> l3 : x^0'=x^post_6, [ x^0==x^post_6 ], cost: 1 Simplified all rules, resulting in: Start location: l4 0: l0 -> l2 : x^0'=-1+x^0, [], cost: 1 1: l2 -> l1 : [ 1<=x^0 ], cost: 1 2: l2 -> l1 : [ 1+x^0<=0 ], cost: 1 3: l1 -> l0 : [], cost: 1 4: l3 -> l0 : [ 1<=x^0 ], cost: 1 5: l4 -> l3 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l4 0: l0 -> l2 : x^0'=-1+x^0, [], cost: 1 1: l2 -> l1 : [ 1<=x^0 ], cost: 1 2: l2 -> l1 : [ 1+x^0<=0 ], cost: 1 3: l1 -> l0 : [], cost: 1 6: l4 -> l0 : [ 1<=x^0 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l4 7: l0 -> l1 : x^0'=-1+x^0, [ 1<=-1+x^0 ], cost: 2 8: l0 -> l1 : x^0'=-1+x^0, [ x^0<=0 ], cost: 2 3: l1 -> l0 : [], cost: 1 6: l4 -> l0 : [ 1<=x^0 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l4 9: l0 -> l0 : x^0'=-1+x^0, [ 1<=-1+x^0 ], cost: 3 10: l0 -> l0 : x^0'=-1+x^0, [ x^0<=0 ], cost: 3 6: l4 -> l0 : [ 1<=x^0 ], cost: 2 Accelerating simple loops of location 0. Accelerating the following rules: 9: l0 -> l0 : x^0'=-1+x^0, [ 1<=-1+x^0 ], cost: 3 10: l0 -> l0 : x^0'=-1+x^0, [ x^0<=0 ], cost: 3 Accelerated rule 9 with metering function -1+x^0, yielding the new rule 11. Accelerated rule 10 with NONTERM, yielding the new rule 12. Removing the simple loops: 9 10. Accelerated all simple loops using metering functions (where possible): Start location: l4 11: l0 -> l0 : x^0'=1, [ 1<=-1+x^0 ], cost: -3+3*x^0 12: l0 -> [5] : [ x^0<=0 ], cost: NONTERM 6: l4 -> l0 : [ 1<=x^0 ], cost: 2 Chained accelerated rules (with incoming rules): Start location: l4 6: l4 -> l0 : [ 1<=x^0 ], cost: 2 13: l4 -> l0 : x^0'=1, [ 1<=-1+x^0 ], cost: -1+3*x^0 Removed unreachable locations (and leaf rules with constant cost): Start location: l4 13: l4 -> l0 : x^0'=1, [ 1<=-1+x^0 ], cost: -1+3*x^0 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l4 13: l4 -> l0 : x^0'=1, [ 1<=-1+x^0 ], cost: -1+3*x^0 Computing asymptotic complexity for rule 13 Solved the limit problem by the following transformations: Created initial limit problem: -1+x^0 (+/+!), -1+3*x^0 (+) [not solved] removing all constraints (solved by SMT) resulting limit problem: [solved] applying transformation rule (C) using substitution {x^0==n} resulting limit problem: [solved] Solution: x^0 / n Resulting cost -1+3*n has complexity: Poly(n^1) Found new complexity Poly(n^1). Obtained the following overall complexity (w.r.t. the length of the input n): Complexity: Poly(n^1) Cpx degree: 1 Solved cost: -1+3*n Rule cost: -1+3*x^0 Rule guard: [ 1<=-1+x^0 ] WORST_CASE(Omega(n^1),?)