NO ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l4 0: l0 -> l1 : x^0'=x^post_1, y^0'=y^post_1, [ 1+x^0<=0 && x^0==x^post_1 && y^0==y^post_1 ], cost: 1 1: l0 -> l2 : x^0'=x^post_2, y^0'=y^post_2, [ 0<=x^0 && x^post_2==-y^0+x^0 && y^0==y^post_2 ], cost: 1 2: l2 -> l0 : x^0'=x^post_3, y^0'=y^post_3, [ x^0==x^post_3 && y^0==y^post_3 ], cost: 1 3: l3 -> l0 : x^0'=x^post_4, y^0'=y^post_4, [ 1+y^0+x^0<=0 && 1<=x^0 && x^0==x^post_4 && y^0==y^post_4 ], cost: 1 4: l4 -> l3 : x^0'=x^post_5, y^0'=y^post_5, [ x^0==x^post_5 && y^0==y^post_5 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 4: l4 -> l3 : x^0'=x^post_5, y^0'=y^post_5, [ x^0==x^post_5 && y^0==y^post_5 ], cost: 1 Removed unreachable and leaf rules: Start location: l4 1: l0 -> l2 : x^0'=x^post_2, y^0'=y^post_2, [ 0<=x^0 && x^post_2==-y^0+x^0 && y^0==y^post_2 ], cost: 1 2: l2 -> l0 : x^0'=x^post_3, y^0'=y^post_3, [ x^0==x^post_3 && y^0==y^post_3 ], cost: 1 3: l3 -> l0 : x^0'=x^post_4, y^0'=y^post_4, [ 1+y^0+x^0<=0 && 1<=x^0 && x^0==x^post_4 && y^0==y^post_4 ], cost: 1 4: l4 -> l3 : x^0'=x^post_5, y^0'=y^post_5, [ x^0==x^post_5 && y^0==y^post_5 ], cost: 1 Simplified all rules, resulting in: Start location: l4 1: l0 -> l2 : x^0'=-y^0+x^0, [ 0<=x^0 ], cost: 1 2: l2 -> l0 : [], cost: 1 3: l3 -> l0 : [ 1+y^0+x^0<=0 && 1<=x^0 ], cost: 1 4: l4 -> l3 : [], cost: 1 ### Simplification by acceleration and chaining ### Eliminated locations (on linear paths): Start location: l4 6: l0 -> l0 : x^0'=-y^0+x^0, [ 0<=x^0 ], cost: 2 5: l4 -> l0 : [ 1+y^0+x^0<=0 && 1<=x^0 ], cost: 2 Accelerating simple loops of location 0. Accelerating the following rules: 6: l0 -> l0 : x^0'=-y^0+x^0, [ 0<=x^0 ], cost: 2 [test] deduced invariant y^0<=0 Accelerated rule 6 with non-termination, yielding the new rule 7. Accelerated rule 6 with non-termination, yielding the new rule 8. Accelerated rule 6 with backward acceleration, yielding the new rule 9. [accelerate] Nesting with 0 inner and 1 outer candidates Also removing duplicate rules: 8. Accelerated all simple loops using metering functions (where possible): Start location: l4 6: l0 -> l0 : x^0'=-y^0+x^0, [ 0<=x^0 ], cost: 2 7: l0 -> [5] : [ y^0==0 && x^0==0 ], cost: NONTERM 9: l0 -> [5] : [ 0<=x^0 && y^0<=0 ], cost: NONTERM 5: l4 -> l0 : [ 1+y^0+x^0<=0 && 1<=x^0 ], cost: 2 Chained accelerated rules (with incoming rules): Start location: l4 5: l4 -> l0 : [ 1+y^0+x^0<=0 && 1<=x^0 ], cost: 2 10: l4 -> l0 : x^0'=-y^0+x^0, [ 1+y^0+x^0<=0 && 1<=x^0 ], cost: 4 11: l4 -> [5] : [ 1+y^0+x^0<=0 && 1<=x^0 && y^0<=0 ], cost: NONTERM Removed unreachable locations (and leaf rules with constant cost): Start location: l4 11: l4 -> [5] : [ 1+y^0+x^0<=0 && 1<=x^0 && y^0<=0 ], cost: NONTERM ### Computing asymptotic complexity ### Fully simplified ITS problem Start location: l4 11: l4 -> [5] : [ 1+y^0+x^0<=0 && 1<=x^0 && y^0<=0 ], cost: NONTERM Computing asymptotic complexity for rule 11 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: [ 1+y^0+x^0<=0 && 1<=x^0 ] NO