WORST_CASE(Omega(1),?) ### Pre-processing the ITS problem ### Initial linear ITS problem Start location: l6 0: l0 -> l1 : 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 && y^0==y^post_1 ], cost: 1 1: l0 -> l1 : 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 && y^0==y^post_2 ], cost: 1 2: l1 -> l2 : x^0'=x^post_3, y^0'=y^post_3, [ 1+x^0<=1 && x^0==x^post_3 && y^0==y^post_3 ], cost: 1 3: l1 -> l2 : x^0'=x^post_4, y^0'=y^post_4, [ 2<=x^0 && x^0==x^post_4 && y^0==y^post_4 ], cost: 1 4: l2 -> l3 : x^0'=x^post_5, y^0'=y^post_5, [ 1+x^0<=2 && x^0==x^post_5 && y^0==y^post_5 ], cost: 1 5: l2 -> l3 : x^0'=x^post_6, y^0'=y^post_6, [ 3<=x^0 && x^0==x^post_6 && y^0==y^post_6 ], cost: 1 6: l3 -> l4 : x^0'=x^post_7, y^0'=y^post_7, [ 1+x^0<=4 && x^0==x^post_7 && y^0==y^post_7 ], cost: 1 7: l3 -> l4 : x^0'=x^post_8, y^0'=y^post_8, [ 5<=x^0 && x^0==x^post_8 && y^0==y^post_8 ], cost: 1 8: l4 -> l0 : x^0'=x^post_9, y^0'=y^post_9, [ y^post_9==y^post_9 && x^0==x^post_9 ], cost: 1 9: l5 -> l1 : x^0'=x^post_10, y^0'=y^post_10, [ x^post_10==x^post_10 && 1<=x^post_10 && y^0==y^post_10 ], cost: 1 10: l6 -> l5 : x^0'=x^post_11, y^0'=y^post_11, [ x^0==x^post_11 && y^0==y^post_11 ], cost: 1 Checking for constant complexity: The following rule is satisfiable with cost >= 1, yielding constant complexity: 10: l6 -> l5 : x^0'=x^post_11, y^0'=y^post_11, [ x^0==x^post_11 && y^0==y^post_11 ], cost: 1 Simplified all rules, resulting in: Start location: l6 0: l0 -> l1 : x^0'=1+3*x^0, [ 1-x^0+2*y^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ -x^0+2*y^0==0 ], cost: 1 2: l1 -> l2 : [ 1+x^0<=1 ], cost: 1 3: l1 -> l2 : [ 2<=x^0 ], cost: 1 4: l2 -> l3 : [ 1+x^0<=2 ], cost: 1 5: l2 -> l3 : [ 3<=x^0 ], cost: 1 6: l3 -> l4 : [ 1+x^0<=4 ], cost: 1 7: l3 -> l4 : [ 5<=x^0 ], cost: 1 8: l4 -> l0 : y^0'=y^post_9, [], cost: 1 9: l5 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 1 10: 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-x^0+2*y^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ -x^0+2*y^0==0 ], cost: 1 2: l1 -> l2 : [ 1+x^0<=1 ], cost: 1 3: l1 -> l2 : [ 2<=x^0 ], cost: 1 4: l2 -> l3 : [ 1+x^0<=2 ], cost: 1 5: l2 -> l3 : [ 3<=x^0 ], cost: 1 6: l3 -> l4 : [ 1+x^0<=4 ], cost: 1 7: l3 -> l4 : [ 5<=x^0 ], cost: 1 8: l4 -> l0 : y^0'=y^post_9, [], cost: 1 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l6 0: l0 -> l1 : x^0'=1+3*x^0, [ 1-x^0+2*y^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ -x^0+2*y^0==0 ], cost: 1 12: l1 -> l3 : [ 1+x^0<=1 ], cost: 2 13: l1 -> l3 : [ 3<=x^0 ], cost: 2 14: l3 -> l0 : y^0'=y^post_9, [ 1+x^0<=4 ], cost: 2 15: l3 -> l0 : y^0'=y^post_9, [ 5<=x^0 ], cost: 2 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l6 0: l0 -> l1 : x^0'=1+3*x^0, [ 1-x^0+2*y^0==0 ], cost: 1 1: l0 -> l1 : x^0'=y^0, [ -x^0+2*y^0==0 ], cost: 1 16: l1 -> l0 : y^0'=y^post_9, [ 1+x^0<=1 ], cost: 4 17: l1 -> l0 : y^0'=y^post_9, [ 3<=x^0 && 1+x^0<=4 ], cost: 4 18: l1 -> l0 : y^0'=y^post_9, [ 5<=x^0 ], cost: 4 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 Eliminated locations (on tree-shaped paths): Start location: l6 19: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 1+x^0<=1 && 1+2*y^post_9-x^0==0 ], cost: 5 20: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 1+x^0<=1 && 2*y^post_9-x^0==0 ], cost: 5 21: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 3<=x^0 && 1+x^0<=4 && 1+2*y^post_9-x^0==0 ], cost: 5 22: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 5<=x^0 && 1+2*y^post_9-x^0==0 ], cost: 5 23: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 5<=x^0 && 2*y^post_9-x^0==0 ], cost: 5 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 Accelerating simple loops of location 1. Simplified some of the simple loops (and removed duplicate rules). Accelerating the following rules: 19: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 1+x^0<=1 && 1+2*y^post_9-x^0==0 ], cost: 5 20: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 1+x^0<=1 && 2*y^post_9-x^0==0 ], cost: 5 21: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 3-x^0==0 && 1+2*y^post_9-x^0==0 ], cost: 5 22: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 5<=x^0 && 1+2*y^post_9-x^0==0 ], cost: 5 23: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 5<=x^0 && 2*y^post_9-x^0==0 ], cost: 5 Found no metering function for rule 19. Accelerated rule 20 with NONTERM (after strengthening guard), yielding the new rule 24. Accelerated rule 21 with metering function meter (where 7*meter==1+2*y^post_9-x^0), yielding the new rule 25. Found no metering function for rule 22. Accelerated rule 23 with NONTERM (after strengthening guard), yielding the new rule 26. Removing the simple loops: 21. Accelerated all simple loops using metering functions (where possible): Start location: l6 19: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 1+x^0<=1 && 1+2*y^post_9-x^0==0 ], cost: 5 20: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 1+x^0<=1 && 2*y^post_9-x^0==0 ], cost: 5 22: l1 -> l1 : x^0'=1+3*x^0, y^0'=y^post_9, [ 5<=x^0 && 1+2*y^post_9-x^0==0 ], cost: 5 23: l1 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 5<=x^0 && 2*y^post_9-x^0==0 ], cost: 5 24: l1 -> [7] : [ 1+x^0<=1 && 2*y^post_9-x^0==0 && y^post_9==0 ], cost: NONTERM 25: l1 -> l1 : x^0'=-1/2+3^meter*x^0+1/2*3^meter, y^0'=y^post_9, [ 3-x^0==0 && 1+2*y^post_9-x^0==0 && 7*meter==1+2*y^post_9-x^0 && meter>=1 ], cost: 5*meter 26: l1 -> [7] : [ 5<=x^0 && 2*y^post_9-x^0==0 && 5<=y^post_9 && y^post_9==0 ], cost: NONTERM 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 Chained accelerated rules (with incoming rules): Start location: l6 11: l6 -> l1 : x^0'=x^post_10, [ 1<=x^post_10 ], cost: 2 27: l6 -> l1 : x^0'=4+6*y^post_9, y^0'=y^post_9, [ 5<=1+2*y^post_9 ], cost: 7 28: l6 -> l1 : x^0'=y^post_9, y^0'=y^post_9, [ 5<=2*y^post_9 ], 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: [ x^0==x^post_11 && y^0==y^post_11 ] WORST_CASE(Omega(1),?)