WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l6 0: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_1, __disjvr_1^0'=__disjvr_1^post_1, __disjvr_2^0'=__disjvr_2^post_1, x^0'=x^post_1, y^0'=y^post_1, [ 1+2*y^0<=x^0 && x^0<=1+2*y^0 && x^post_1==1+3*x^0 && __disjvr_0^0==__disjvr_0^post_1 && __disjvr_1^0==__disjvr_1^post_1 && __disjvr_2^0==__disjvr_2^post_1 && y^0==y^post_1 ], cost: 1 1: l0 -> l1 : __disjvr_0^0'=__disjvr_0^post_2, __disjvr_1^0'=__disjvr_1^post_2, __disjvr_2^0'=__disjvr_2^post_2, x^0'=x^post_2, y^0'=y^post_2, [ 2*y^0<=x^0 && x^0<=2*y^0 && x^post_2==y^0 && __disjvr_0^0==__disjvr_0^post_2 && __disjvr_1^0==__disjvr_1^post_2 && __disjvr_2^0==__disjvr_2^post_2 && y^0==y^post_2 ], cost: 1 2: l1 -> l2 : __disjvr_0^0'=__disjvr_0^post_3, __disjvr_1^0'=__disjvr_1^post_3, __disjvr_2^0'=__disjvr_2^post_3, x^0'=x^post_3, y^0'=y^post_3, [ __disjvr_0^post_3==__disjvr_0^0 && __disjvr_0^0==__disjvr_0^post_3 && __disjvr_1^0==__disjvr_1^post_3 && __disjvr_2^0==__disjvr_2^post_3 && x^0==x^post_3 && y^0==y^post_3 ], cost: 1 3: l2 -> l3 : __disjvr_0^0'=__disjvr_0^post_4, __disjvr_1^0'=__disjvr_1^post_4, __disjvr_2^0'=__disjvr_2^post_4, x^0'=x^post_4, y^0'=y^post_4, [ __disjvr_1^post_4==__disjvr_1^0 && __disjvr_0^0==__disjvr_0^post_4 && __disjvr_1^0==__disjvr_1^post_4 && __disjvr_2^0==__disjvr_2^post_4 && x^0==x^post_4 && y^0==y^post_4 ], cost: 1 4: l3 -> l4 : __disjvr_0^0'=__disjvr_0^post_5, __disjvr_1^0'=__disjvr_1^post_5, __disjvr_2^0'=__disjvr_2^post_5, x^0'=x^post_5, y^0'=y^post_5, [ __disjvr_2^post_5==__disjvr_2^0 && __disjvr_0^0==__disjvr_0^post_5 && __disjvr_1^0==__disjvr_1^post_5 && __disjvr_2^0==__disjvr_2^post_5 && x^0==x^post_5 && y^0==y^post_5 ], cost: 1 5: l4 -> l0 : __disjvr_0^0'=__disjvr_0^post_6, __disjvr_1^0'=__disjvr_1^post_6, __disjvr_2^0'=__disjvr_2^post_6, x^0'=x^post_6, y^0'=y^post_6, [ y^post_6==y^post_6 && __disjvr_0^0==__disjvr_0^post_6 && __disjvr_1^0==__disjvr_1^post_6 && __disjvr_2^0==__disjvr_2^post_6 && x^0==x^post_6 ], cost: 1 6: l5 -> l1 : __disjvr_0^0'=__disjvr_0^post_7, __disjvr_1^0'=__disjvr_1^post_7, __disjvr_2^0'=__disjvr_2^post_7, x^0'=x^post_7, y^0'=y^post_7, [ x^post_7==x^post_7 && 1<=x^post_7 && __disjvr_0^0==__disjvr_0^post_7 && __disjvr_1^0==__disjvr_1^post_7 && __disjvr_2^0==__disjvr_2^post_7 && y^0==y^post_7 ], cost: 1 7: l6 -> l5 : __disjvr_0^0'=__disjvr_0^post_8, __disjvr_1^0'=__disjvr_1^post_8, __disjvr_2^0'=__disjvr_2^post_8, x^0'=x^post_8, y^0'=y^post_8, [ __disjvr_0^0==__disjvr_0^post_8 && __disjvr_1^0==__disjvr_1^post_8 && __disjvr_2^0==__disjvr_2^post_8 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 7: l6 -> l5 : __disjvr_0^0'=__disjvr_0^post_8, __disjvr_1^0'=__disjvr_1^post_8, __disjvr_2^0'=__disjvr_2^post_8, x^0'=x^post_8, y^0'=y^post_8, [ __disjvr_0^0==__disjvr_0^post_8 && __disjvr_1^0==__disjvr_1^post_8 && __disjvr_2^0==__disjvr_2^post_8 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 Simplified all rules, resulting in: Start location: l6 0: l0 -> l1 : x^0'=1+3*x^0, [ 1+2*y^0-x^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ 2*y^0-x^0==0 ], cost: 1 2: l1 -> l2 : [], cost: 1 3: l2 -> l3 : [], cost: 1 4: l3 -> l4 : [], cost: 1 5: l4 -> l0 : y^0'=y^post_6, [], cost: 1 6: l5 -> l1 : x^0'=x^post_7, [ 1<=x^post_7 ], cost: 1 7: l6 -> l5 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l6 0: l0 -> l1 : x^0'=1+3*x^0, [ 1+2*y^0-x^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ 2*y^0-x^0==0 ], cost: 1 11: l1 -> l0 : y^0'=y^post_6, [], cost: 4 8: l6 -> l1 : x^0'=x^post_7, [ 1<=x^post_7 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l6 12: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_6, [ 1-x^0+2*y^post_6==0 ], cost: 5 13: l1 -> l1 : x^0'=y^post_6, y^0'=y^post_6, [ -x^0+2*y^post_6==0 ], cost: 5 8: l6 -> l1 : x^0'=x^post_7, [ 1<=x^post_7 ], cost: 2 Accelerating simple loops of location 1. Accelerating the following rules: 12: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_6, [ 1-x^0+2*y^post_6==0 ], cost: 5 13: l1 -> l1 : x^0'=y^post_6, y^0'=y^post_6, [ -x^0+2*y^post_6==0 ], cost: 5 [test] deduced invariant 1-x^0<=0 [test] deduced invariant -x^0<=0 Failed to prove monotonicity of the guard of rule 12. [test] deduced pseudo-invariant -x^0+y^post_6<=0, also trying x^0-y^post_6<=-1 Accelerated rule 13 with non-termination, yielding the new rule 14. Accelerated rule 13 with non-termination, yielding the new rule 15. [accelerate] Nesting with 1 inner and 2 outer candidates Nested simple loops 13 (outer loop) and 12 (inner loop) with Rule(1 | 1-x^0+2*y^post_6==0, -1-3*x^0+2*y^post_6==0, | NONTERM || 7 | ), resulting in the new rules: 16, 17. Removing the simple loops: 13. Accelerated all simple loops using metering functions (where possible): Start location: l6 12: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_6, [ 1-x^0+2*y^post_6==0 ], cost: 5 14: l1 -> [7] : [ -x^0+2*y^post_6==0 && y^post_6==0 ], cost: NONTERM 15: l1 -> [7] : [ -x^0+2*y^post_6==0 && -x^0+y^post_6<=0 && y^post_6==0 ], cost: NONTERM 16: l1 -> [7] : [ 1-x^0+2*y^post_6==0 && -1-3*x^0+2*y^post_6==0 ], cost: NONTERM 17: l1 -> [7] : [ -x^0+2*y^post_6==0 && 1+y^post_6==0 && -1-y^post_6==0 ], cost: NONTERM 8: l6 -> l1 : x^0'=x^post_7, [ 1<=x^post_7 ], cost: 2 Chained accelerated rules (with incoming rules): Start location: l6 8: l6 -> l1 : x^0'=x^post_7, [ 1<=x^post_7 ], cost: 2 18: l6 -> l1 : x^0'=4+6*y^post_6, y^0'=y^post_6, [ 1<=1+2*y^post_6 ], cost: 7 Removed unreachable locations (and leaf rules with constant cost): Start location: l6 ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l6 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: [ __disjvr_0^0==__disjvr_0^post_8 && __disjvr_1^0==__disjvr_1^post_8 && __disjvr_2^0==__disjvr_2^post_8 && x^0==x^post_8 && y^0==y^post_8 ] WORST_CASE(Omega(1),?)