WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l3 0: l0 -> l1 : x^0'=x^post_1, y^0'=y^post_1, z^0'=z^post_1, [ y^post_1==-1+y^0 && z^post_1==z^0+y^post_1 && x^0==x^post_1 ], cost: 1 1: l0 -> l1 : x^0'=x^post_2, y^0'=y^post_2, z^0'=z^post_2, [ x^post_2==-1+x^0 && y^post_2==-1+y^0 && z^0==z^post_2 ], cost: 1 2: l1 -> l0 : x^0'=x^post_3, y^0'=y^post_3, z^0'=z^post_3, [ 0<=x^0 && y^0<=z^0 && x^0==x^post_3 && y^0==y^post_3 && z^0==z^post_3 ], cost: 1 3: l2 -> l1 : x^0'=x^post_4, y^0'=y^post_4, z^0'=z^post_4, [ x^0==x^post_4 && y^0==y^post_4 && z^0==z^post_4 ], cost: 1 4: l3 -> l2 : x^0'=x^post_5, y^0'=y^post_5, z^0'=z^post_5, [ x^0==x^post_5 && y^0==y^post_5 && z^0==z^post_5 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 4: l3 -> l2 : x^0'=x^post_5, y^0'=y^post_5, z^0'=z^post_5, [ x^0==x^post_5 && y^0==y^post_5 && z^0==z^post_5 ], cost: 1 Simplified all rules, resulting in: Start location: l3 0: l0 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [], cost: 1 1: l0 -> l1 : x^0'=-1+x^0, y^0'=-1+y^0, [], cost: 1 2: l1 -> l0 : [ 0<=x^0 && y^0<=z^0 ], cost: 1 3: l2 -> l1 : [], cost: 1 4: l3 -> l2 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l3 0: l0 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [], cost: 1 1: l0 -> l1 : x^0'=-1+x^0, y^0'=-1+y^0, [], cost: 1 2: l1 -> l0 : [ 0<=x^0 && y^0<=z^0 ], cost: 1 5: l3 -> l1 : [], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l3 6: l1 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [ 0<=x^0 && y^0<=z^0 ], cost: 2 7: l1 -> l1 : x^0'=-1+x^0, y^0'=-1+y^0, [ 0<=x^0 && y^0<=z^0 ], cost: 2 5: l3 -> l1 : [], cost: 2 Accelerating simple loops of location 1. Accelerating the following rules: 6: l1 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [ 0<=x^0 && y^0<=z^0 ], cost: 2 7: l1 -> l1 : x^0'=-1+x^0, y^0'=-1+y^0, [ 0<=x^0 && y^0<=z^0 ], cost: 2 [test] deduced pseudo-invariant y^0<=0, also trying -y^0<=-1 Accelerated rule 6 with backward acceleration, yielding the new rule 8. Accelerated rule 6 with backward acceleration, yielding the new rule 9. Accelerated rule 7 with backward acceleration, yielding the new rule 10. [accelerate] Nesting with 3 inner and 2 outer candidates Removing the simple loops: 7. Accelerated all simple loops using metering functions (where possible): Start location: l3 6: l1 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [ 0<=x^0 && y^0<=z^0 ], cost: 2 8: l1 -> l1 : y^0'=y^0-k, z^0'=y^0*k-1/2*k^2+z^0-1/2*k, [ 0<=x^0 && y^0<=0 && k>=0 && 1+y^0-k<=1/2-1/2*(-1+k)^2+z^0+(-1+k)*y^0-1/2*k ], cost: 2*k 9: l1 -> l1 : y^0'=0, z^0'=-1/2*y^0+1/2*y^0^2+z^0, [ 0<=x^0 && y^0<=z^0 && y^0>=0 ], cost: 2*y^0 10: l1 -> l1 : x^0'=-1, y^0'=-1+y^0-x^0, [ y^0<=z^0 && 1+x^0>=0 ], cost: 2+2*x^0 5: l3 -> l1 : [], cost: 2 Chained accelerated rules (with incoming rules): Start location: l3 5: l3 -> l1 : [], cost: 2 11: l3 -> l1 : y^0'=-1+y^0, z^0'=-1+y^0+z^0, [ 0<=x^0 && y^0<=z^0 ], cost: 4 12: l3 -> l1 : y^0'=y^0-k, z^0'=y^0*k-1/2*k^2+z^0-1/2*k, [ 0<=x^0 && y^0<=0 && k>=0 && 1+y^0-k<=1/2-1/2*(-1+k)^2+z^0+(-1+k)*y^0-1/2*k ], cost: 2+2*k 13: l3 -> l1 : y^0'=0, z^0'=-1/2*y^0+1/2*y^0^2+z^0, [ 0<=x^0 && y^0<=z^0 && y^0>=0 ], cost: 2+2*y^0 14: l3 -> l1 : x^0'=-1, y^0'=-1+y^0-x^0, [ y^0<=z^0 && 1+x^0>=0 ], cost: 4+2*x^0 Removed unreachable locations (and leaf rules with constant cost): Start location: l3 12: l3 -> l1 : y^0'=y^0-k, z^0'=y^0*k-1/2*k^2+z^0-1/2*k, [ 0<=x^0 && y^0<=0 && k>=0 && 1+y^0-k<=1/2-1/2*(-1+k)^2+z^0+(-1+k)*y^0-1/2*k ], cost: 2+2*k 13: l3 -> l1 : y^0'=0, z^0'=-1/2*y^0+1/2*y^0^2+z^0, [ 0<=x^0 && y^0<=z^0 && y^0>=0 ], cost: 2+2*y^0 14: l3 -> l1 : x^0'=-1, y^0'=-1+y^0-x^0, [ y^0<=z^0 && 1+x^0>=0 ], cost: 4+2*x^0 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l3 12: l3 -> l1 : y^0'=y^0-k, z^0'=y^0*k-1/2*k^2+z^0-1/2*k, [ 0<=x^0 && y^0<=0 && k>=0 && 1+y^0-k<=1/2-1/2*(-1+k)^2+z^0+(-1+k)*y^0-1/2*k ], cost: 2+2*k 13: l3 -> l1 : y^0'=0, z^0'=-1/2*y^0+1/2*y^0^2+z^0, [ 0<=x^0 && y^0<=z^0 && y^0>=0 ], cost: 2+2*y^0 14: l3 -> l1 : x^0'=-1, y^0'=-1+y^0-x^0, [ y^0<=z^0 && 1+x^0>=0 ], cost: 4+2*x^0 Computing asymptotic complexity for rule 12 Resulting cost 0 has complexity: Unknown Computing asymptotic complexity for rule 14 Resulting cost 0 has complexity: Unknown Computing asymptotic complexity for rule 13 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: [ x^0==x^post_5 && y^0==y^post_5 && z^0==z^post_5 ] WORST_CASE(Omega(1),?)