WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 7: [3] -> [6] : z'=-1+z, [ x<0 ], cost: 1 5: [4] -> [5] : [ 0<=0 ], cost: 1 6: [5] -> [3] : z'=1+z, x'=z^2-z*y, [], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 Removed unreachable and leaf rules: Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 5: [4] -> [5] : [ 0<=0 ], cost: 1 6: [5] -> [3] : z'=1+z, x'=z^2-z*y, [], cost: 1 Simplified all rules, resulting in: Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 5: [4] -> [5] : [], cost: 1 6: [5] -> [3] : z'=1+z, x'=z^2-z*y, [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 9: [3] -> [3] : z'=1+z, x'=z^2-z*y, [ x>=0 ], cost: 3 Accelerating simple loops of location 3. Accelerating the following rules: 9: [3] -> [3] : z'=1+z, x'=z^2-z*y, [ x>=0 ], cost: 3 Failed to prove monotonicity of the guard of rule 9. [accelerate] Nesting with 1 inner and 1 outer candidates Accelerated all simple loops using metering functions (where possible): Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 9: [3] -> [3] : z'=1+z, x'=z^2-z*y, [ x>=0 ], cost: 3 Chained accelerated rules (with incoming rules): Start location: [0] 0: [0] -> [1] : z'=1+z, [ z>=4 ], cost: 1 1: [1] -> [2] : z'=1+z, [ x>=0 ], cost: 1 2: [1] -> [2] : z'=-1+z, [ x<0 ], cost: 1 3: [2] -> [3] : [ y>=1 && y<=5 ], cost: 1 10: [2] -> [3] : z'=1+z, x'=z^2-z*y, [ y>=1 && y<=5 && x>=0 ], cost: 4 Removed unreachable locations (and leaf rules with constant cost): Start location: [0] ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: [0] 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: [ z>=4 ] WORST_CASE(Omega(1),?)