WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l4 0: l0 -> l1 : i^0'=i^post_1, j^0'=j^post_1, [ 20<=j^0 && i^0==i^post_1 && j^0==j^post_1 ], cost: 1 1: l0 -> l2 : i^0'=i^post_2, j^0'=j^post_2, [ 1+j^0<=20 && i^0==i^post_2 && j^0==j^post_2 ], cost: 1 2: l2 -> l0 : i^0'=i^post_3, j^0'=j^post_3, [ j^post_3==2+j^0 && i^post_3==2+j^post_3 ], cost: 1 3: l3 -> l2 : i^0'=i^post_4, j^0'=j^post_4, [ j^post_4==0 && i^0==i^post_4 ], cost: 1 4: l4 -> l3 : i^0'=i^post_5, j^0'=j^post_5, [ i^0==i^post_5 && j^0==j^post_5 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 4: l4 -> l3 : i^0'=i^post_5, j^0'=j^post_5, [ i^0==i^post_5 && j^0==j^post_5 ], cost: 1 Removed unreachable and leaf rules: Start location: l4 1: l0 -> l2 : i^0'=i^post_2, j^0'=j^post_2, [ 1+j^0<=20 && i^0==i^post_2 && j^0==j^post_2 ], cost: 1 2: l2 -> l0 : i^0'=i^post_3, j^0'=j^post_3, [ j^post_3==2+j^0 && i^post_3==2+j^post_3 ], cost: 1 3: l3 -> l2 : i^0'=i^post_4, j^0'=j^post_4, [ j^post_4==0 && i^0==i^post_4 ], cost: 1 4: l4 -> l3 : i^0'=i^post_5, j^0'=j^post_5, [ i^0==i^post_5 && j^0==j^post_5 ], cost: 1 Simplified all rules, resulting in: Start location: l4 1: l0 -> l2 : [ 1+j^0<=20 ], cost: 1 2: l2 -> l0 : i^0'=4+j^0, j^0'=2+j^0, [], cost: 1 3: l3 -> l2 : j^0'=0, [], cost: 1 4: l4 -> l3 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l4 6: l2 -> l2 : i^0'=4+j^0, j^0'=2+j^0, [ 3+j^0<=20 ], cost: 2 5: l4 -> l2 : j^0'=0, [], cost: 2 Accelerating simple loops of location 2. Accelerating the following rules: 6: l2 -> l2 : i^0'=4+j^0, j^0'=2+j^0, [ 3+j^0<=20 ], cost: 2 Accelerated rule 6 with backward acceleration, yielding the new rule 7. [accelerate] Nesting with 1 inner and 1 outer candidates Removing the simple loops: 6. Accelerated all simple loops using metering functions (where possible): Start location: l4 7: l2 -> l2 : i^0'=2+j^0+2*k, j^0'=j^0+2*k, [ k>=1 && 1+j^0+2*k<=20 ], cost: 2*k 5: l4 -> l2 : j^0'=0, [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l4 5: l4 -> l2 : j^0'=0, [], cost: 2 8: l4 -> l2 : i^0'=2+2*k, j^0'=2*k, [ k>=1 && 1+2*k<=20 ], cost: 2+2*k Removed unreachable locations (and leaf rules with constant cost): Start location: l4 8: l4 -> l2 : i^0'=2+2*k, j^0'=2*k, [ k>=1 && 1+2*k<=20 ], cost: 2+2*k ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l4 8: l4 -> l2 : i^0'=2+2*k, j^0'=2*k, [ k>=1 && 1+2*k<=20 ], cost: 2+2*k Computing asymptotic complexity for rule 8 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: [ i^0==i^post_5 && j^0==j^post_5 ] WORST_CASE(Omega(1),?)