WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: __init 0: f1 -> f2 : arg1'=arg1P_1, arg2'=arg2P_1, arg3'=arg3P_1, arg4'=arg4P_1, [ arg2==arg2P_1 && arg3==arg3P_1 && arg4==arg4P_1 ], cost: 1 1: f2 -> f3 : arg1'=arg1P_2, arg2'=arg2P_2, arg3'=arg3P_2, arg4'=arg4P_2, [ arg1==arg1P_2 && arg3==arg3P_2 && arg4==arg4P_2 ], cost: 1 11: f3 -> f4 : arg1'=arg1P_12, arg2'=arg2P_12, arg3'=arg3P_12, arg4'=arg4P_12, [ arg2>0 && arg1>0 && arg1==arg1P_12 && arg2==arg2P_12 && arg3==arg3P_12 && arg4==arg4P_12 ], cost: 1 13: f3 -> f12 : arg1'=arg1P_14, arg2'=arg2P_14, arg3'=arg3P_14, arg4'=arg4P_14, [ arg2<=0 && arg1==arg1P_14 && arg2==arg2P_14 && arg3==arg3P_14 && arg4==arg4P_14 ], cost: 1 14: f3 -> f12 : arg1'=arg1P_15, arg2'=arg2P_15, arg3'=arg3P_15, arg4'=arg4P_15, [ arg1<=0 && arg1==arg1P_15 && arg2==arg2P_15 && arg3==arg3P_15 && arg4==arg4P_15 ], cost: 1 2: f4 -> f5 : arg1'=arg1P_3, arg2'=arg2P_3, arg3'=arg3P_3, arg4'=arg4P_3, [ arg1==arg1P_3 && arg2==arg2P_3 && arg2==arg3P_3 && arg4==arg4P_3 ], cost: 1 3: f5 -> f6 : arg1'=arg1P_4, arg2'=arg2P_4, arg3'=arg3P_4, arg4'=arg4P_4, [ arg1==arg1P_4 && arg2==arg2P_4 && arg3==arg3P_4 && arg1==arg4P_4 ], cost: 1 5: f6 -> f7 : arg1'=arg1P_6, arg2'=arg2P_6, arg3'=arg3P_6, arg4'=arg4P_6, [ arg4>=arg2 && arg2>0 && arg1==arg1P_6 && arg2==arg2P_6 && arg3==arg3P_6 && arg4==arg4P_6 ], cost: 1 7: f6 -> f9 : arg1'=arg1P_8, arg2'=arg2P_8, arg3'=arg3P_8, arg4'=arg4P_8, [ arg4 f9 : arg1'=arg1P_9, arg2'=arg2P_9, arg3'=arg3P_9, arg4'=arg4P_9, [ arg2<=0 && arg1==arg1P_9 && arg2==arg2P_9 && arg3==arg3P_9 && arg4==arg4P_9 ], cost: 1 4: f7 -> f8 : arg1'=arg1P_5, arg2'=arg2P_5, arg3'=arg3P_5, arg4'=arg4P_5, [ arg4P_5==-arg2+arg4 && arg1==arg1P_5 && arg2==arg2P_5 && arg3==arg3P_5 ], cost: 1 6: f8 -> f6 : arg1'=arg1P_7, arg2'=arg2P_7, arg3'=arg3P_7, arg4'=arg4P_7, [ arg1==arg1P_7 && arg2==arg2P_7 && arg3==arg3P_7 && arg4==arg4P_7 ], cost: 1 9: f9 -> f10 : arg1'=arg1P_10, arg2'=arg2P_10, arg3'=arg3P_10, arg4'=arg4P_10, [ arg1==arg1P_10 && arg4==arg2P_10 && arg3==arg3P_10 && arg4==arg4P_10 ], cost: 1 10: f10 -> f11 : arg1'=arg1P_11, arg2'=arg2P_11, arg3'=arg3P_11, arg4'=arg4P_11, [ arg3==arg1P_11 && arg2==arg2P_11 && arg3==arg3P_11 && arg4==arg4P_11 ], cost: 1 12: f11 -> f3 : arg1'=arg1P_13, arg2'=arg2P_13, arg3'=arg3P_13, arg4'=arg4P_13, [ arg1==arg1P_13 && arg2==arg2P_13 && arg3==arg3P_13 && arg4==arg4P_13 ], cost: 1 15: __init -> f1 : arg1'=arg1P_16, arg2'=arg2P_16, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 15: __init -> f1 : arg1'=arg1P_16, arg2'=arg2P_16, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 1 Removed unreachable and leaf rules: Start location: __init 0: f1 -> f2 : arg1'=arg1P_1, arg2'=arg2P_1, arg3'=arg3P_1, arg4'=arg4P_1, [ arg2==arg2P_1 && arg3==arg3P_1 && arg4==arg4P_1 ], cost: 1 1: f2 -> f3 : arg1'=arg1P_2, arg2'=arg2P_2, arg3'=arg3P_2, arg4'=arg4P_2, [ arg1==arg1P_2 && arg3==arg3P_2 && arg4==arg4P_2 ], cost: 1 11: f3 -> f4 : arg1'=arg1P_12, arg2'=arg2P_12, arg3'=arg3P_12, arg4'=arg4P_12, [ arg2>0 && arg1>0 && arg1==arg1P_12 && arg2==arg2P_12 && arg3==arg3P_12 && arg4==arg4P_12 ], cost: 1 2: f4 -> f5 : arg1'=arg1P_3, arg2'=arg2P_3, arg3'=arg3P_3, arg4'=arg4P_3, [ arg1==arg1P_3 && arg2==arg2P_3 && arg2==arg3P_3 && arg4==arg4P_3 ], cost: 1 3: f5 -> f6 : arg1'=arg1P_4, arg2'=arg2P_4, arg3'=arg3P_4, arg4'=arg4P_4, [ arg1==arg1P_4 && arg2==arg2P_4 && arg3==arg3P_4 && arg1==arg4P_4 ], cost: 1 5: f6 -> f7 : arg1'=arg1P_6, arg2'=arg2P_6, arg3'=arg3P_6, arg4'=arg4P_6, [ arg4>=arg2 && arg2>0 && arg1==arg1P_6 && arg2==arg2P_6 && arg3==arg3P_6 && arg4==arg4P_6 ], cost: 1 7: f6 -> f9 : arg1'=arg1P_8, arg2'=arg2P_8, arg3'=arg3P_8, arg4'=arg4P_8, [ arg4 f9 : arg1'=arg1P_9, arg2'=arg2P_9, arg3'=arg3P_9, arg4'=arg4P_9, [ arg2<=0 && arg1==arg1P_9 && arg2==arg2P_9 && arg3==arg3P_9 && arg4==arg4P_9 ], cost: 1 4: f7 -> f8 : arg1'=arg1P_5, arg2'=arg2P_5, arg3'=arg3P_5, arg4'=arg4P_5, [ arg4P_5==-arg2+arg4 && arg1==arg1P_5 && arg2==arg2P_5 && arg3==arg3P_5 ], cost: 1 6: f8 -> f6 : arg1'=arg1P_7, arg2'=arg2P_7, arg3'=arg3P_7, arg4'=arg4P_7, [ arg1==arg1P_7 && arg2==arg2P_7 && arg3==arg3P_7 && arg4==arg4P_7 ], cost: 1 9: f9 -> f10 : arg1'=arg1P_10, arg2'=arg2P_10, arg3'=arg3P_10, arg4'=arg4P_10, [ arg1==arg1P_10 && arg4==arg2P_10 && arg3==arg3P_10 && arg4==arg4P_10 ], cost: 1 10: f10 -> f11 : arg1'=arg1P_11, arg2'=arg2P_11, arg3'=arg3P_11, arg4'=arg4P_11, [ arg3==arg1P_11 && arg2==arg2P_11 && arg3==arg3P_11 && arg4==arg4P_11 ], cost: 1 12: f11 -> f3 : arg1'=arg1P_13, arg2'=arg2P_13, arg3'=arg3P_13, arg4'=arg4P_13, [ arg1==arg1P_13 && arg2==arg2P_13 && arg3==arg3P_13 && arg4==arg4P_13 ], cost: 1 15: __init -> f1 : arg1'=arg1P_16, arg2'=arg2P_16, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 1 Simplified all rules, resulting in: Start location: __init 0: f1 -> f2 : arg1'=arg1P_1, [], cost: 1 1: f2 -> f3 : arg2'=arg2P_2, [], cost: 1 11: f3 -> f4 : [ arg2>0 && arg1>0 ], cost: 1 2: f4 -> f5 : arg3'=arg2, [], cost: 1 3: f5 -> f6 : arg4'=arg1, [], cost: 1 5: f6 -> f7 : [ arg4>=arg2 && arg2>0 ], cost: 1 7: f6 -> f9 : [ arg4 f9 : [ arg2<=0 ], cost: 1 4: f7 -> f8 : arg4'=-arg2+arg4, [], cost: 1 6: f8 -> f6 : [], cost: 1 9: f9 -> f10 : arg2'=arg4, [], cost: 1 10: f10 -> f11 : arg1'=arg3, [], cost: 1 12: f11 -> f3 : [], cost: 1 15: __init -> f1 : arg1'=arg1P_16, arg2'=arg2P_16, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: __init 19: f3 -> f6 : arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 ], cost: 3 7: f6 -> f9 : [ arg4 f9 : [ arg2<=0 ], cost: 1 21: f6 -> f6 : arg4'=-arg2+arg4, [ arg4>=arg2 && arg2>0 ], cost: 3 23: f9 -> f3 : arg1'=arg3, arg2'=arg4, [], cost: 3 17: __init -> f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Accelerating simple loops of location 5. Accelerating the following rules: 21: f6 -> f6 : arg4'=-arg2+arg4, [ arg4>=arg2 && arg2>0 ], cost: 3 Accelerated rule 21 with backward acceleration, yielding the new rule 24. [accelerate] Nesting with 1 inner and 1 outer candidates Removing the simple loops: 21. Accelerated all simple loops using metering functions (where possible): Start location: __init 19: f3 -> f6 : arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 ], cost: 3 7: f6 -> f9 : [ arg4 f9 : [ arg2<=0 ], cost: 1 24: f6 -> f6 : arg4'=-arg2*k+arg4, [ arg2>0 && k>=0 && -arg2*(-1+k)+arg4>=arg2 ], cost: 3*k 23: f9 -> f3 : arg1'=arg3, arg2'=arg4, [], cost: 3 17: __init -> f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Chained accelerated rules (with incoming rules): Start location: __init 19: f3 -> f6 : arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 ], cost: 3 25: f3 -> f6 : arg3'=arg2, arg4'=-arg2*k+arg1, [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 ], cost: 3+3*k 7: f6 -> f9 : [ arg4 f9 : [ arg2<=0 ], cost: 1 23: f9 -> f3 : arg1'=arg3, arg2'=arg4, [], cost: 3 17: __init -> f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Eliminated locations (on tree-shaped paths): Start location: __init 26: f3 -> f9 : arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 && arg1 f9 : arg3'=arg2, arg4'=-arg2*k+arg1, [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 && -arg2*k+arg1 [14] : [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 ], cost: 3+3*k 23: f9 -> f3 : arg1'=arg3, arg2'=arg4, [], cost: 3 17: __init -> f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Eliminated locations (on tree-shaped paths): Start location: __init 28: f3 -> [14] : [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 ], cost: 3+3*k 29: f3 -> f3 : arg1'=arg2, arg2'=arg1, arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 && arg1 f3 : arg1'=arg2, arg2'=-arg2*k+arg1, arg3'=arg2, arg4'=-arg2*k+arg1, [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 && -arg2*k+arg1 f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Accelerating simple loops of location 2. Accelerating the following rules: 29: f3 -> f3 : arg1'=arg2, arg2'=arg1, arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 && arg1 f3 : arg1'=arg2, arg2'=-arg2*k+arg1, arg3'=arg2, arg4'=-arg2*k+arg1, [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 && -arg2*k+arg1 [14] : [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 ], cost: 3+3*k 29: f3 -> f3 : arg1'=arg2, arg2'=arg1, arg3'=arg2, arg4'=arg1, [ arg2>0 && arg1>0 && arg1 f3 : arg1'=arg2, arg2'=-arg2*k+arg1, arg3'=arg2, arg4'=-arg2*k+arg1, [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 && -arg2*k+arg1 f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 Chained accelerated rules (with incoming rules): Start location: __init 28: f3 -> [14] : [ arg2>0 && arg1>0 && k>=0 && -arg2*(-1+k)+arg1>=arg2 ], cost: 3+3*k 17: __init -> f3 : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [], cost: 3 31: __init -> f3 : arg1'=arg2P_2, arg2'=arg1P_1, arg3'=arg2P_2, arg4'=arg1P_1, [ arg2P_2>0 && arg1P_1>0 && arg1P_1 f3 : arg1'=arg2P_2, arg2'=-arg2P_2*k+arg1P_1, arg3'=arg2P_2, arg4'=-arg2P_2*k+arg1P_1, [ arg2P_2>0 && arg1P_1>0 && k>=0 && -arg2P_2*(-1+k)+arg1P_1>=arg2P_2 && -arg2P_2*k+arg1P_1 [14] : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [ arg2P_2>0 && arg1P_1>0 && k>=0 && -arg2P_2*(-1+k)+arg1P_1>=arg2P_2 ], cost: 6+3*k 34: __init -> [14] : arg1'=arg2P_2, arg2'=arg1P_1, arg3'=arg2P_2, arg4'=arg1P_1, [ arg2P_2>0 && arg1P_1>0 && arg1P_1=0 && arg2P_2-(-1+k)*arg1P_1>=arg1P_1 ], cost: 13+3*k 35: __init -> [14] : arg1'=arg2P_2, arg2'=-arg2P_2*k+arg1P_1, arg3'=arg2P_2, arg4'=-arg2P_2*k+arg1P_1, [ arg2P_2>0 && arg1P_1>0 && k>=0 && -arg2P_2*k+arg1P_10 && arg2P_2+(arg2P_2*k-arg1P_1)*(-1+k)>=-arg2P_2*k+arg1P_1 ], cost: 13+6*k ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: __init 33: __init -> [14] : arg1'=arg1P_1, arg2'=arg2P_2, arg3'=arg3P_16, arg4'=arg4P_16, [ arg2P_2>0 && arg1P_1>0 && k>=0 && -arg2P_2*(-1+k)+arg1P_1>=arg2P_2 ], cost: 6+3*k 34: __init -> [14] : arg1'=arg2P_2, arg2'=arg1P_1, arg3'=arg2P_2, arg4'=arg1P_1, [ arg2P_2>0 && arg1P_1>0 && arg1P_1=0 && arg2P_2-(-1+k)*arg1P_1>=arg1P_1 ], cost: 13+3*k 35: __init -> [14] : arg1'=arg2P_2, arg2'=-arg2P_2*k+arg1P_1, arg3'=arg2P_2, arg4'=-arg2P_2*k+arg1P_1, [ arg2P_2>0 && arg1P_1>0 && k>=0 && -arg2P_2*k+arg1P_10 && arg2P_2+(arg2P_2*k-arg1P_1)*(-1+k)>=-arg2P_2*k+arg1P_1 ], cost: 13+6*k Computing asymptotic complexity for rule 33 Resulting cost 0 has complexity: Unknown Computing asymptotic complexity for rule 34 Simplified the guard: 34: __init -> [14] : arg1'=arg2P_2, arg2'=arg1P_1, arg3'=arg2P_2, arg4'=arg1P_1, [ arg1P_1>0 && arg1P_1=0 && arg2P_2-(-1+k)*arg1P_1>=arg1P_1 ], cost: 13+3*k Resulting cost 0 has complexity: Unknown Computing asymptotic complexity for rule 35 Simplified the guard: 35: __init -> [14] : arg1'=arg2P_2, arg2'=-arg2P_2*k+arg1P_1, arg3'=arg2P_2, arg4'=-arg2P_2*k+arg1P_1, [ k>=0 && -arg2P_2*k+arg1P_10 && arg2P_2+(arg2P_2*k-arg1P_1)*(-1+k)>=-arg2P_2*k+arg1P_1 ], cost: 13+6*k Resulting cost 0 has complexity: Unknown Obtained the following overall complexity (w.r.t. the length of the input n): Complexity: Constant Cpx degree: 0 Solved cost: 1 Rule cost: 1 Rule guard: [] WORST_CASE(Omega(1),?)