WORST_CASE(Omega(n^1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l4 0: l0 -> l1 : 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 && y^0==y^post_1 ], cost: 1 1: l0 -> l1 : 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 && x^0==x^post_2 ], cost: 1 2: l0 -> l1 : 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 && y^0==y^post_3 ], cost: 1 3: l0 -> l1 : 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 && x^0==x^post_4 ], cost: 1 4: l1 -> l2 : x^0'=x^post_5, y^0'=y^post_5, [ 1+x^0<=0 && x^0==x^post_5 && y^0==y^post_5 ], cost: 1 5: l1 -> l2 : x^0'=x^post_6, y^0'=y^post_6, [ 1<=x^0 && x^0==x^post_6 && y^0==y^post_6 ], cost: 1 6: l2 -> l0 : x^0'=x^post_7, y^0'=y^post_7, [ 1+y^0<=0 && x^0==x^post_7 && y^0==y^post_7 ], cost: 1 7: l2 -> l0 : x^0'=x^post_8, y^0'=y^post_8, [ 1<=y^0 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 8: l3 -> l1 : x^0'=x^post_9, y^0'=y^post_9, [ x^0==x^post_9 && y^0==y^post_9 ], cost: 1 9: l4 -> l3 : x^0'=x^post_10, y^0'=y^post_10, [ x^0==x^post_10 && y^0==y^post_10 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 9: l4 -> l3 : x^0'=x^post_10, y^0'=y^post_10, [ x^0==x^post_10 && y^0==y^post_10 ], 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 : [ 1+x^0<=0 ], cost: 1 5: l1 -> l2 : [ 1<=x^0 ], cost: 1 6: l2 -> l0 : [ 1+y^0<=0 ], cost: 1 7: l2 -> l0 : [ 1<=y^0 ], cost: 1 8: l3 -> l1 : [], cost: 1 9: 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 4: l1 -> l2 : [ 1+x^0<=0 ], cost: 1 5: l1 -> l2 : [ 1<=x^0 ], cost: 1 6: l2 -> l0 : [ 1+y^0<=0 ], cost: 1 7: l2 -> l0 : [ 1<=y^0 ], cost: 1 10: l4 -> l1 : [], cost: 2 Eliminated locations (on tree-shaped 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 11: l1 -> l0 : [ 1+x^0<=0 && 1+y^0<=0 ], cost: 2 12: l1 -> l0 : [ 1+x^0<=0 && 1<=y^0 ], cost: 2 13: l1 -> l0 : [ 1<=x^0 && 1+y^0<=0 ], cost: 2 14: l1 -> l0 : [ 1<=x^0 && 1<=y^0 ], cost: 2 10: l4 -> l1 : [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l4 15: l1 -> l1 : y^0'=1+y^0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 16: l1 -> l1 : x^0'=-1+x^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 17: l1 -> l1 : x^0'=1+x^0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 18: l1 -> l1 : y^0'=1+y^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 19: l1 -> l1 : x^0'=-1+x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 20: l1 -> l1 : y^0'=-1+y^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 21: l1 -> l1 : x^0'=1+x^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 22: l1 -> l1 : y^0'=-1+y^0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 10: l4 -> l1 : [], cost: 2 Accelerating simple loops of location 1. Accelerating the following rules: 15: l1 -> l1 : y^0'=1+y^0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 16: l1 -> l1 : x^0'=-1+x^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 17: l1 -> l1 : x^0'=1+x^0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 18: l1 -> l1 : y^0'=1+y^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 3 19: l1 -> l1 : x^0'=-1+x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3 20: l1 -> l1 : y^0'=-1+y^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 21: l1 -> l1 : x^0'=1+x^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 3 22: l1 -> l1 : y^0'=-1+y^0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 3 Accelerated rule 15 with metering function -y^0, yielding the new rule 23. Accelerated rule 16 with metering function x^0-y^0, yielding the new rule 24. Accelerated rule 17 with metering function -x^0, yielding the new rule 25. Accelerated rule 18 with metering function -x^0-y^0, yielding the new rule 26. Accelerated rule 19 with metering function x^0, yielding the new rule 27. Accelerated rule 20 with metering function -1+x^0+y^0, yielding the new rule 28. Accelerated rule 21 with metering function -x^0+y^0, yielding the new rule 29. Accelerated rule 22 with metering function y^0, yielding the new rule 30. Removing the simple loops: 15 16 17 18 19 20 21 22. Accelerated all simple loops using metering functions (where possible): Start location: l4 23: l1 -> l1 : y^0'=0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: -3*y^0 24: l1 -> l1 : x^0'=y^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3*x^0-3*y^0 25: l1 -> l1 : x^0'=0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: -3*x^0 26: l1 -> l1 : y^0'=-x^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: -3*x^0-3*y^0 27: l1 -> l1 : x^0'=0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 3*x^0 28: l1 -> l1 : y^0'=1-x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: -3+3*x^0+3*y^0 29: l1 -> l1 : x^0'=y^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: -3*x^0+3*y^0 30: l1 -> l1 : y^0'=0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 3*y^0 10: l4 -> l1 : [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l4 10: l4 -> l1 : [], cost: 2 31: l4 -> l1 : y^0'=0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*y^0 32: l4 -> l1 : x^0'=y^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 33: l4 -> l1 : x^0'=0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0 34: l4 -> l1 : y^0'=-x^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 35: l4 -> l1 : x^0'=0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0 36: l4 -> l1 : y^0'=1-x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 37: l4 -> l1 : x^0'=y^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 38: l4 -> l1 : y^0'=0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 2+3*y^0 Removed unreachable locations (and leaf rules with constant cost): Start location: l4 31: l4 -> l1 : y^0'=0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*y^0 32: l4 -> l1 : x^0'=y^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 33: l4 -> l1 : x^0'=0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0 34: l4 -> l1 : y^0'=-x^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 35: l4 -> l1 : x^0'=0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0 36: l4 -> l1 : y^0'=1-x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 37: l4 -> l1 : x^0'=y^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 38: l4 -> l1 : y^0'=0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 2+3*y^0 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l4 31: l4 -> l1 : y^0'=0, [ 1+x^0<=0 && 1+y^0<=0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*y^0 32: l4 -> l1 : x^0'=y^0, [ 1+x^0<=0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0-3*y^0 33: l4 -> l1 : x^0'=0, [ 1+x^0<=0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0 34: l4 -> l1 : y^0'=-x^0, [ 1+x^0<=0 && 1<=y^0 && x^0<=y^0 && 1+x^0<=-y^0 ], cost: 2-3*x^0-3*y^0 35: l4 -> l1 : x^0'=0, [ 1<=x^0 && 1+y^0<=0 && y^0<=1-x^0 && 1+y^0<=x^0 ], cost: 2+3*x^0 36: l4 -> l1 : y^0'=1-x^0, [ 1<=x^0 && 1+y^0<=0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: -1+3*x^0+3*y^0 37: l4 -> l1 : x^0'=y^0, [ 1<=x^0 && 1<=y^0 && -x^0<=y^0 && 1+x^0<=y^0 ], cost: 2-3*x^0+3*y^0 38: l4 -> l1 : y^0'=0, [ 1<=x^0 && 1<=y^0 && y^0<=x^0 && 2-y^0<=x^0 ], cost: 2+3*y^0 Computing asymptotic complexity for rule 31 Simplified the guard: 31: l4 -> l1 : y^0'=0, [ 1+y^0<=0 && x^0<=y^0 ], cost: 2-3*y^0 Solved the limit problem by the following transformations: Created initial limit problem: 1-x^0+y^0 (+/+!), 2-3*y^0 (+), -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+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: 2+3*n Rule cost: 2-3*y^0 Rule guard: [ 1+y^0<=0 && x^0<=y^0 ] WORST_CASE(Omega(n^1),?)