WORST_CASE(Omega(n^2),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l9 0: l0 -> l1 : guard^0'=guard^post_1, i^0'=i^post_1, j^0'=j^post_1, n^0'=n^post_1, [ n^0<=j^0 && i^post_1==1+i^0 && guard^0==guard^post_1 && j^0==j^post_1 && n^0==n^post_1 ], cost: 1 1: l0 -> l2 : guard^0'=guard^post_2, i^0'=i^post_2, j^0'=j^post_2, n^0'=n^post_2, [ 1+j^0<=n^0 && guard^post_2==guard^post_2 && i^0==i^post_2 && j^0==j^post_2 && n^0==n^post_2 ], cost: 1 4: l1 -> l3 : guard^0'=guard^post_5, i^0'=i^post_5, j^0'=j^post_5, n^0'=n^post_5, [ guard^0==guard^post_5 && i^0==i^post_5 && j^0==j^post_5 && n^0==n^post_5 ], cost: 1 8: l2 -> l6 : guard^0'=guard^post_9, i^0'=i^post_9, j^0'=j^post_9, n^0'=n^post_9, [ guard^0<=0 && 0<=guard^0 && guard^0==guard^post_9 && i^0==i^post_9 && j^0==j^post_9 && n^0==n^post_9 ], cost: 1 9: l2 -> l7 : guard^0'=guard^post_10, i^0'=i^post_10, j^0'=j^post_10, n^0'=n^post_10, [ 1<=guard^0 && guard^0==guard^post_10 && i^0==i^post_10 && j^0==j^post_10 && n^0==n^post_10 ], cost: 1 10: l2 -> l7 : guard^0'=guard^post_11, i^0'=i^post_11, j^0'=j^post_11, n^0'=n^post_11, [ 1+guard^0<=0 && guard^0==guard^post_11 && i^0==i^post_11 && j^0==j^post_11 && n^0==n^post_11 ], cost: 1 2: l3 -> l4 : guard^0'=guard^post_3, i^0'=i^post_3, j^0'=j^post_3, n^0'=n^post_3, [ n^0<=i^0 && guard^0==guard^post_3 && i^0==i^post_3 && j^0==j^post_3 && n^0==n^post_3 ], cost: 1 3: l3 -> l5 : guard^0'=guard^post_4, i^0'=i^post_4, j^0'=j^post_4, n^0'=n^post_4, [ 1+i^0<=n^0 && j^post_4==1+i^0 && guard^0==guard^post_4 && i^0==i^post_4 && n^0==n^post_4 ], cost: 1 5: l5 -> l0 : guard^0'=guard^post_6, i^0'=i^post_6, j^0'=j^post_6, n^0'=n^post_6, [ guard^0==guard^post_6 && i^0==i^post_6 && j^0==j^post_6 && n^0==n^post_6 ], cost: 1 6: l6 -> l5 : guard^0'=guard^post_7, i^0'=i^post_7, j^0'=j^post_7, n^0'=n^post_7, [ j^post_7==1+j^0 && guard^0==guard^post_7 && i^0==i^post_7 && n^0==n^post_7 ], cost: 1 7: l7 -> l6 : guard^0'=guard^post_8, i^0'=i^post_8, j^0'=j^post_8, n^0'=n^post_8, [ j^post_8==-1+j^0 && n^post_8==-1+n^0 && guard^0==guard^post_8 && i^0==i^post_8 ], cost: 1 11: l8 -> l1 : guard^0'=guard^post_12, i^0'=i^post_12, j^0'=j^post_12, n^0'=n^post_12, [ i^post_12==0 && guard^0==guard^post_12 && j^0==j^post_12 && n^0==n^post_12 ], cost: 1 12: l9 -> l8 : guard^0'=guard^post_13, i^0'=i^post_13, j^0'=j^post_13, n^0'=n^post_13, [ guard^0==guard^post_13 && i^0==i^post_13 && j^0==j^post_13 && n^0==n^post_13 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 12: l9 -> l8 : guard^0'=guard^post_13, i^0'=i^post_13, j^0'=j^post_13, n^0'=n^post_13, [ guard^0==guard^post_13 && i^0==i^post_13 && j^0==j^post_13 && n^0==n^post_13 ], cost: 1 Removed unreachable and leaf rules: Start location: l9 0: l0 -> l1 : guard^0'=guard^post_1, i^0'=i^post_1, j^0'=j^post_1, n^0'=n^post_1, [ n^0<=j^0 && i^post_1==1+i^0 && guard^0==guard^post_1 && j^0==j^post_1 && n^0==n^post_1 ], cost: 1 1: l0 -> l2 : guard^0'=guard^post_2, i^0'=i^post_2, j^0'=j^post_2, n^0'=n^post_2, [ 1+j^0<=n^0 && guard^post_2==guard^post_2 && i^0==i^post_2 && j^0==j^post_2 && n^0==n^post_2 ], cost: 1 4: l1 -> l3 : guard^0'=guard^post_5, i^0'=i^post_5, j^0'=j^post_5, n^0'=n^post_5, [ guard^0==guard^post_5 && i^0==i^post_5 && j^0==j^post_5 && n^0==n^post_5 ], cost: 1 8: l2 -> l6 : guard^0'=guard^post_9, i^0'=i^post_9, j^0'=j^post_9, n^0'=n^post_9, [ guard^0<=0 && 0<=guard^0 && guard^0==guard^post_9 && i^0==i^post_9 && j^0==j^post_9 && n^0==n^post_9 ], cost: 1 9: l2 -> l7 : guard^0'=guard^post_10, i^0'=i^post_10, j^0'=j^post_10, n^0'=n^post_10, [ 1<=guard^0 && guard^0==guard^post_10 && i^0==i^post_10 && j^0==j^post_10 && n^0==n^post_10 ], cost: 1 10: l2 -> l7 : guard^0'=guard^post_11, i^0'=i^post_11, j^0'=j^post_11, n^0'=n^post_11, [ 1+guard^0<=0 && guard^0==guard^post_11 && i^0==i^post_11 && j^0==j^post_11 && n^0==n^post_11 ], cost: 1 3: l3 -> l5 : guard^0'=guard^post_4, i^0'=i^post_4, j^0'=j^post_4, n^0'=n^post_4, [ 1+i^0<=n^0 && j^post_4==1+i^0 && guard^0==guard^post_4 && i^0==i^post_4 && n^0==n^post_4 ], cost: 1 5: l5 -> l0 : guard^0'=guard^post_6, i^0'=i^post_6, j^0'=j^post_6, n^0'=n^post_6, [ guard^0==guard^post_6 && i^0==i^post_6 && j^0==j^post_6 && n^0==n^post_6 ], cost: 1 6: l6 -> l5 : guard^0'=guard^post_7, i^0'=i^post_7, j^0'=j^post_7, n^0'=n^post_7, [ j^post_7==1+j^0 && guard^0==guard^post_7 && i^0==i^post_7 && n^0==n^post_7 ], cost: 1 7: l7 -> l6 : guard^0'=guard^post_8, i^0'=i^post_8, j^0'=j^post_8, n^0'=n^post_8, [ j^post_8==-1+j^0 && n^post_8==-1+n^0 && guard^0==guard^post_8 && i^0==i^post_8 ], cost: 1 11: l8 -> l1 : guard^0'=guard^post_12, i^0'=i^post_12, j^0'=j^post_12, n^0'=n^post_12, [ i^post_12==0 && guard^0==guard^post_12 && j^0==j^post_12 && n^0==n^post_12 ], cost: 1 12: l9 -> l8 : guard^0'=guard^post_13, i^0'=i^post_13, j^0'=j^post_13, n^0'=n^post_13, [ guard^0==guard^post_13 && i^0==i^post_13 && j^0==j^post_13 && n^0==n^post_13 ], cost: 1 Simplified all rules, resulting in: Start location: l9 0: l0 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 1 1: l0 -> l2 : guard^0'=guard^post_2, [ 1+j^0<=n^0 ], cost: 1 4: l1 -> l3 : [], cost: 1 8: l2 -> l6 : [ guard^0==0 ], cost: 1 9: l2 -> l7 : [ 1<=guard^0 ], cost: 1 10: l2 -> l7 : [ 1+guard^0<=0 ], cost: 1 3: l3 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 1 5: l5 -> l0 : [], cost: 1 6: l6 -> l5 : j^0'=1+j^0, [], cost: 1 7: l7 -> l6 : j^0'=-1+j^0, n^0'=-1+n^0, [], cost: 1 11: l8 -> l1 : i^0'=0, [], cost: 1 12: l9 -> l8 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l9 0: l0 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 1 1: l0 -> l2 : guard^0'=guard^post_2, [ 1+j^0<=n^0 ], cost: 1 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 8: l2 -> l6 : [ guard^0==0 ], cost: 1 9: l2 -> l7 : [ 1<=guard^0 ], cost: 1 10: l2 -> l7 : [ 1+guard^0<=0 ], cost: 1 5: l5 -> l0 : [], cost: 1 6: l6 -> l5 : j^0'=1+j^0, [], cost: 1 7: l7 -> l6 : j^0'=-1+j^0, n^0'=-1+n^0, [], cost: 1 13: l9 -> l1 : i^0'=0, [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l9 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 8: l2 -> l6 : [ guard^0==0 ], cost: 1 17: l2 -> l6 : j^0'=-1+j^0, n^0'=-1+n^0, [ 1<=guard^0 ], cost: 2 18: l2 -> l6 : j^0'=-1+j^0, n^0'=-1+n^0, [ 1+guard^0<=0 ], cost: 2 15: l5 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 2 16: l5 -> l2 : guard^0'=guard^post_2, [ 1+j^0<=n^0 ], cost: 2 6: l6 -> l5 : j^0'=1+j^0, [], cost: 1 13: l9 -> l1 : i^0'=0, [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l9 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 15: l5 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 2 19: l5 -> l6 : guard^0'=guard^post_2, [ 1+j^0<=n^0 && guard^post_2==0 ], cost: 3 20: l5 -> l6 : guard^0'=guard^post_2, j^0'=-1+j^0, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1<=guard^post_2 ], cost: 4 21: l5 -> l6 : guard^0'=guard^post_2, j^0'=-1+j^0, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1+guard^post_2<=0 ], cost: 4 6: l6 -> l5 : j^0'=1+j^0, [], cost: 1 13: l9 -> l1 : i^0'=0, [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l9 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 15: l5 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 2 22: l5 -> l5 : guard^0'=guard^post_2, j^0'=1+j^0, [ 1+j^0<=n^0 && guard^post_2==0 ], cost: 4 23: l5 -> l5 : guard^0'=guard^post_2, j^0'=j^0, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1<=guard^post_2 ], cost: 5 24: l5 -> l5 : guard^0'=guard^post_2, j^0'=j^0, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1+guard^post_2<=0 ], cost: 5 13: l9 -> l1 : i^0'=0, [], cost: 2 Accelerating simple loops of location 5. Simplified some of the simple loops (and removed duplicate rules). Accelerating the following rules: 22: l5 -> l5 : guard^0'=0, j^0'=1+j^0, [ 1+j^0<=n^0 ], cost: 4 23: l5 -> l5 : guard^0'=guard^post_2, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1<=guard^post_2 ], cost: 5 24: l5 -> l5 : guard^0'=guard^post_2, n^0'=-1+n^0, [ 1+j^0<=n^0 && 1+guard^post_2<=0 ], cost: 5 Accelerated rule 22 with metering function -j^0+n^0, yielding the new rule 25. Accelerated rule 23 with metering function -j^0+n^0, yielding the new rule 26. Accelerated rule 24 with metering function -j^0+n^0, yielding the new rule 27. Removing the simple loops: 22 23 24. Accelerated all simple loops using metering functions (where possible): Start location: l9 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 15: l5 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 2 25: l5 -> l5 : guard^0'=0, j^0'=n^0, [ 1+j^0<=n^0 ], cost: -4*j^0+4*n^0 26: l5 -> l5 : guard^0'=guard^post_2, n^0'=j^0, [ 1+j^0<=n^0 && 1<=guard^post_2 ], cost: -5*j^0+5*n^0 27: l5 -> l5 : guard^0'=guard^post_2, n^0'=j^0, [ 1+j^0<=n^0 && 1+guard^post_2<=0 ], cost: -5*j^0+5*n^0 13: l9 -> l1 : i^0'=0, [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l9 14: l1 -> l5 : j^0'=1+i^0, [ 1+i^0<=n^0 ], cost: 2 28: l1 -> l5 : guard^0'=0, j^0'=n^0, [ 2+i^0<=n^0 ], cost: -2+4*n^0-4*i^0 29: l1 -> l5 : guard^0'=guard^post_2, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1<=guard^post_2 ], cost: -3+5*n^0-5*i^0 30: l1 -> l5 : guard^0'=guard^post_2, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1+guard^post_2<=0 ], cost: -3+5*n^0-5*i^0 15: l5 -> l1 : i^0'=1+i^0, [ n^0<=j^0 ], cost: 2 13: l9 -> l1 : i^0'=0, [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l9 31: l1 -> l1 : i^0'=1+i^0, j^0'=1+i^0, [ 1+i^0<=n^0 && n^0<=1+i^0 ], cost: 4 32: l1 -> l1 : guard^0'=0, i^0'=1+i^0, j^0'=n^0, [ 2+i^0<=n^0 ], cost: 4*n^0-4*i^0 33: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1<=guard^post_2 ], cost: -1+5*n^0-5*i^0 34: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1+guard^post_2<=0 ], cost: -1+5*n^0-5*i^0 13: l9 -> l1 : i^0'=0, [], cost: 2 Accelerating simple loops of location 1. Simplified some of the simple loops (and removed duplicate rules). Accelerating the following rules: 31: l1 -> l1 : i^0'=1+i^0, j^0'=1+i^0, [ 1-n^0+i^0==0 ], cost: 4 32: l1 -> l1 : guard^0'=0, i^0'=1+i^0, j^0'=n^0, [ 2+i^0<=n^0 ], cost: 4*n^0-4*i^0 33: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1<=guard^post_2 ], cost: -1+5*n^0-5*i^0 34: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1+guard^post_2<=0 ], cost: -1+5*n^0-5*i^0 Accelerated rule 31 with metering function n^0-i^0, yielding the new rule 35. Accelerated rule 32 with metering function -1+n^0-i^0, yielding the new rule 36. Found no metering function for rule 33. Found no metering function for rule 34. Removing the simple loops: 31 32. Accelerated all simple loops using metering functions (where possible): Start location: l9 33: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1<=guard^post_2 ], cost: -1+5*n^0-5*i^0 34: l1 -> l1 : guard^0'=guard^post_2, i^0'=1+i^0, j^0'=1+i^0, n^0'=1+i^0, [ 2+i^0<=n^0 && 1+guard^post_2<=0 ], cost: -1+5*n^0-5*i^0 35: l1 -> l1 : i^0'=n^0, j^0'=n^0, [ 1-n^0+i^0==0 ], cost: 4*n^0-4*i^0 36: l1 -> l1 : guard^0'=0, i^0'=-1+n^0, j^0'=n^0, [ 2+i^0<=n^0 ], cost: -2-2*(-1+n^0-i^0)^2-4*(-1+n^0-i^0)*i^0+2*n^0+4*n^0*(-1+n^0-i^0)-2*i^0 13: l9 -> l1 : i^0'=0, [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l9 13: l9 -> l1 : i^0'=0, [], cost: 2 37: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1<=guard^post_2 ], cost: 1+5*n^0 38: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1+guard^post_2<=0 ], cost: 1+5*n^0 39: l9 -> l1 : i^0'=n^0, j^0'=n^0, [ 1-n^0==0 ], cost: 2+4*n^0 40: l9 -> l1 : guard^0'=0, i^0'=-1+n^0, j^0'=n^0, [ 2<=n^0 ], cost: -2*(-1+n^0)^2+2*n^0+4*(-1+n^0)*n^0 Removed unreachable locations (and leaf rules with constant cost): Start location: l9 37: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1<=guard^post_2 ], cost: 1+5*n^0 38: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1+guard^post_2<=0 ], cost: 1+5*n^0 39: l9 -> l1 : i^0'=n^0, j^0'=n^0, [ 1-n^0==0 ], cost: 2+4*n^0 40: l9 -> l1 : guard^0'=0, i^0'=-1+n^0, j^0'=n^0, [ 2<=n^0 ], cost: -2*(-1+n^0)^2+2*n^0+4*(-1+n^0)*n^0 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l9 37: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1<=guard^post_2 ], cost: 1+5*n^0 38: l9 -> l1 : guard^0'=guard^post_2, i^0'=1, j^0'=1, n^0'=1, [ 2<=n^0 && 1+guard^post_2<=0 ], cost: 1+5*n^0 39: l9 -> l1 : i^0'=n^0, j^0'=n^0, [ 1-n^0==0 ], cost: 2+4*n^0 40: l9 -> l1 : guard^0'=0, i^0'=-1+n^0, j^0'=n^0, [ 2<=n^0 ], cost: -2*(-1+n^0)^2+2*n^0+4*(-1+n^0)*n^0 Computing asymptotic complexity for rule 37 Solved the limit problem by the following transformations: Created initial limit problem: 1+5*n^0 (+), guard^post_2 (+/+!), -1+n^0 (+/+!) [not solved] removing all constraints (solved by SMT) resulting limit problem: [solved] applying transformation rule (C) using substitution {guard^post_2==n,n^0==n} resulting limit problem: [solved] Solution: guard^post_2 / n n^0 / n Resulting cost 1+5*n has complexity: Poly(n^1) Found new complexity Poly(n^1). Computing asymptotic complexity for rule 40 Solved the limit problem by the following transformations: Created initial limit problem: -2+2*n^0^2+2*n^0 (+), -1+n^0 (+/+!) [not solved] removing all constraints (solved by SMT) resulting limit problem: [solved] applying transformation rule (C) using substitution {n^0==n} resulting limit problem: [solved] Solution: n^0 / n Resulting cost -2+2*n+2*n^2 has complexity: Poly(n^2) Found new complexity Poly(n^2). Obtained the following overall complexity (w.r.t. the length of the input n): Complexity: Poly(n^2) Cpx degree: 2 Solved cost: -2+2*n+2*n^2 Rule cost: -2*(-1+n^0)^2+2*n^0+4*(-1+n^0)*n^0 Rule guard: [ 2<=n^0 ] WORST_CASE(Omega(n^2),?)