NO ### 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>=2 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 7: [3] -> [6] : [ x<0 ], cost: 1 5: [4] -> [5] : a'=z^2, b'=z*y, [ 0<=0 ], cost: 1 6: [5] -> [3] : x'=-b+a, [], 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>=2 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 5: [4] -> [5] : a'=z^2, b'=z*y, [ 0<=0 ], cost: 1 6: [5] -> [3] : x'=-b+a, [], 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>=2 ], cost: 1 4: [3] -> [4] : [ x>=0 ], cost: 1 5: [4] -> [5] : a'=z^2, b'=z*y, [], cost: 1 6: [5] -> [3] : x'=-b+a, [], 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>=2 ], cost: 1 9: [3] -> [3] : x'=z^2-z*y, a'=z^2, b'=z*y, [ x>=0 ], cost: 3 Accelerating simple loops of location 3. Accelerating the following rules: 9: [3] -> [3] : x'=z^2-z*y, a'=z^2, b'=z*y, [ x>=0 ], cost: 3 Accelerated rule 9 with non-termination, yielding the new rule 10. [accelerate] Nesting with 0 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>=2 ], cost: 1 9: [3] -> [3] : x'=z^2-z*y, a'=z^2, b'=z*y, [ x>=0 ], cost: 3 10: [3] -> [7] : [ x>=0 && z^2-z*y>=0 ], cost: NONTERM 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>=2 ], cost: 1 11: [2] -> [3] : x'=z^2-z*y, a'=z^2, b'=z*y, [ y>=2 && x>=0 ], cost: 4 12: [2] -> [7] : [ y>=2 && x>=0 && z^2-z*y>=0 ], cost: NONTERM Removed unreachable locations (and leaf rules with constant cost): 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 12: [2] -> [7] : [ y>=2 && x>=0 && z^2-z*y>=0 ], cost: NONTERM Eliminated locations (on tree-shaped paths): Start location: [0] 13: [0] -> [2] : z'=2+z, [ z>=4 && x>=0 ], cost: 2 14: [0] -> [2] : z'=z, [ z>=4 && x<0 ], cost: 2 12: [2] -> [7] : [ y>=2 && x>=0 && z^2-z*y>=0 ], cost: NONTERM Eliminated locations (on tree-shaped paths): Start location: [0] 15: [0] -> [7] : [ z>=4 && x>=0 && y>=2 && x>=0 && (2+z)^2-y*(2+z)>=0 ], cost: NONTERM ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: [0] 15: [0] -> [7] : [ z>=4 && x>=0 && y>=2 && x>=0 && (2+z)^2-y*(2+z)>=0 ], cost: NONTERM Computing asymptotic complexity for rule 15 Guard is satisfiable, yielding nontermination Resulting cost NONTERM has complexity: Nonterm Found new complexity Nonterm. Obtained the following overall complexity (w.r.t. the length of the input n): Complexity: Nonterm Cpx degree: Nonterm Solved cost: NONTERM Rule cost: NONTERM Rule guard: [ z>=4 && x>=0 && y>=2 && x>=0 && (2+z)^2-y*(2+z)>=0 ] NO