WORST_CASE(Omega(n^1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l4 0: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_1, __disjvr_1^0'=__disjvr_1^post_1, x^0'=x^post_1, y^0'=y^post_1, [ -x^0<=y^0 && 1+x^0<=y^0 && x^post_1==1+x^0 && __disjvr_0^0==__disjvr_0^post_1 && __disjvr_1^0==__disjvr_1^post_1 && y^0==y^post_1 ], cost: 1 1: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_2, __disjvr_1^0'=__disjvr_1^post_2, x^0'=x^post_2, y^0'=y^post_2, [ x^0<=y^0 && 1+x^0<=-y^0 && y^post_2==1+y^0 && __disjvr_0^0==__disjvr_0^post_2 && __disjvr_1^0==__disjvr_1^post_2 && x^0==x^post_2 ], cost: 1 2: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_3, __disjvr_1^0'=__disjvr_1^post_3, x^0'=x^post_3, y^0'=y^post_3, [ y^0<=1-x^0 && 1+y^0<=x^0 && x^post_3==-1+x^0 && __disjvr_0^0==__disjvr_0^post_3 && __disjvr_1^0==__disjvr_1^post_3 && y^0==y^post_3 ], cost: 1 3: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_4, __disjvr_1^0'=__disjvr_1^post_4, x^0'=x^post_4, y^0'=y^post_4, [ y^0<=x^0 && 2-y^0<=x^0 && y^post_4==-1+y^0 && __disjvr_0^0==__disjvr_0^post_4 && __disjvr_1^0==__disjvr_1^post_4 && x^0==x^post_4 ], cost: 1 4: l1 -> l2 : __disjvr_0^0'=__disjvr_0^post_5, __disjvr_1^0'=__disjvr_1^post_5, x^0'=x^post_5, y^0'=y^post_5, [ __disjvr_0^post_5==__disjvr_0^0 && __disjvr_0^0==__disjvr_0^post_5 && __disjvr_1^0==__disjvr_1^post_5 && x^0==x^post_5 && y^0==y^post_5 ], cost: 1 5: l2 -> l0 : __disjvr_0^0'=__disjvr_0^post_6, __disjvr_1^0'=__disjvr_1^post_6, x^0'=x^post_6, y^0'=y^post_6, [ __disjvr_1^post_6==__disjvr_1^0 && __disjvr_0^0==__disjvr_0^post_6 && __disjvr_1^0==__disjvr_1^post_6 && x^0==x^post_6 && y^0==y^post_6 ], cost: 1 6: l3 -> l1 : __disjvr_0^0'=__disjvr_0^post_7, __disjvr_1^0'=__disjvr_1^post_7, x^0'=x^post_7, y^0'=y^post_7, [ __disjvr_0^0==__disjvr_0^post_7 && __disjvr_1^0==__disjvr_1^post_7 && x^0==x^post_7 && y^0==y^post_7 ], cost: 1 7: l4 -> l3 : __disjvr_0^0'=__disjvr_0^post_8, __disjvr_1^0'=__disjvr_1^post_8, x^0'=x^post_8, y^0'=y^post_8, [ __disjvr_0^0==__disjvr_0^post_8 && __disjvr_1^0==__disjvr_1^post_8 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 7: l4 -> l3 : __disjvr_0^0'=__disjvr_0^post_8, __disjvr_1^0'=__disjvr_1^post_8, x^0'=x^post_8, y^0'=y^post_8, [ __disjvr_0^0==__disjvr_0^post_8 && __disjvr_1^0==__disjvr_1^post_8 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 Simplified all rules, resulting in: Start location: l4 0: l0 -> l1 : x^0'=1+x^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 1 1: l0 -> l1 : y^0'=1+y^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 1 2: l0 -> l1 : x^0'=-1+x^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 1 3: l0 -> l1 : y^0'=-1+y^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: 1 4: l1 -> l2 : [], cost: 1 5: l2 -> l0 : [], cost: 1 6: l3 -> l1 : [], cost: 1 7: l4 -> l3 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l4 0: l0 -> l1 : x^0'=1+x^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 1 1: l0 -> l1 : y^0'=1+y^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 1 2: l0 -> l1 : x^0'=-1+x^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 1 3: l0 -> l1 : y^0'=-1+y^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: 1 9: l1 -> l0 : [], cost: 2 8: l4 -> l1 : [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l4 10: l1 -> l1 : x^0'=1+x^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 11: l1 -> l1 : y^0'=1+y^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 12: l1 -> l1 : x^0'=-1+x^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 13: l1 -> l1 : y^0'=-1+y^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 8: l4 -> l1 : [], cost: 2 Accelerating simple loops of location 1. Accelerating the following rules: 10: l1 -> l1 : x^0'=1+x^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 11: l1 -> l1 : y^0'=1+y^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 12: l1 -> l1 : x^0'=-1+x^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 13: l1 -> l1 : y^0'=-1+y^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 Accelerated rule 10 with metering function -x^0+y^0, yielding the new rule 14. Accelerated rule 11 with metering function -x^0-y^0, yielding the new rule 15. Accelerated rule 12 with metering function x^0-y^0, yielding the new rule 16. Accelerated rule 13 with metering function -1+x^0+y^0, yielding the new rule 17. Removing the simple loops: 10 11 12 13. Accelerated all simple loops using metering functions (where possible): Start location: l4 14: l1 -> l1 : x^0'=y^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: -3*x^0+3*y^0 15: l1 -> l1 : y^0'=-x^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: -3*x^0-3*y^0 16: l1 -> l1 : x^0'=y^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3*x^0-3*y^0 17: l1 -> l1 : y^0'=1-x^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: -3+3*x^0+3*y^0 8: l4 -> l1 : [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l4 8: l4 -> l1 : [], cost: 2 18: l4 -> l1 : x^0'=y^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 19: l4 -> l1 : y^0'=-x^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 20: l4 -> l1 : x^0'=y^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 21: l4 -> l1 : y^0'=1-x^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 Removed unreachable locations (and leaf rules with constant cost): Start location: l4 18: l4 -> l1 : x^0'=y^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 19: l4 -> l1 : y^0'=-x^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 20: l4 -> l1 : x^0'=y^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 21: l4 -> l1 : y^0'=1-x^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l4 18: l4 -> l1 : x^0'=y^0, [ -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 19: l4 -> l1 : y^0'=-x^0, [ x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 20: l4 -> l1 : x^0'=y^0, [ y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 21: l4 -> l1 : y^0'=1-x^0, [ y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 Computing asymptotic complexity for rule 18 Solved the limit problem by the following transformations: Created initial limit problem: -x^0+y^0 (+/+!), 1+x^0+y^0 (+/+!), 2-3*x^0+3*y^0 (+) [not solved] removing all constraints (solved by SMT) resulting limit problem: [solved] applying transformation rule (C) using substitution {x^0==-n,y^0==n} resulting limit problem: [solved] Solution: x^0 / -n y^0 / n Resulting cost 2+6*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: 2+6*n Rule cost: 2-3*x^0+3*y^0 Rule guard: [ -x^0<=y^0 && 1+x^0<=y^0 ] WORST_CASE(Omega(n^1),?)