Input TRS: 1: del(.(x,.(y,z))) -> f(=(x,y),x,y,z) 2: f(true(),x,y,z) -> del(.(y,z)) 3: f(false(),x,y,z) -> .(x,del(.(y,z))) 4: =(nil(),nil()) -> true() 5: =(.(x,y),nil()) -> false() 6: =(nil(),.(y,z)) -> false() 7: =(.(x,y),.(u(),v())) -> and(=(x,u()),=(y,v())) Number of strict rules: 7 Direct Order(PosReal,>,Poly) ... failed. Freezing del 1: del❆1_.(x,.(y,z)) -> f(=(x,y),x,y,z) 2: f(true(),x,y,z) -> del❆1_.(y,z) 3: f(false(),x,y,z) -> .(x,del❆1_.(y,z)) 4: =(nil(),nil()) -> true() 5: =(.(x,y),nil()) -> false() 6: =(nil(),.(y,z)) -> false() 7: =(.(x,y),.(u(),v())) -> and(=(x,u()),=(y,v())) 8: del(.(_1,_2)) ->= del❆1_.(_1,_2) Number of strict rules: 7 Direct Order(PosReal,>,Poly) ... failed. Dependency Pairs: #1: #f(true(),x,y,z) -> #del❆1_.(y,z) #2: #=(.(x,y),.(u(),v())) -> #=(x,u()) #3: #=(.(x,y),.(u(),v())) -> #=(y,v()) #4: #f(false(),x,y,z) -> #del❆1_.(y,z) #5: #del❆1_.(x,.(y,z)) -> #f(=(x,y),x,y,z) #6: #del❆1_.(x,.(y,z)) -> #=(x,y) #7: #del(.(_1,_2)) ->? #del❆1_.(_1,_2) Number of SCCs: 1, DPs: 3, edges: 4 SCC { #1 #4 #5 } Removing DPs: Order(PosReal,>,Sum)... succeeded. #del(x1) weight: 0 v() weight: 0 u() weight: 0 and(x1,x2) weight: 0 #del❆1_.(x1,x2) weight: x2 false() weight: 0 true() weight: 0 f(x1,x2,x3,x4) weight: 0 del(x1) weight: 0 =(x1,x2) weight: (/ 1 2) + x2 nil() weight: 0 #f(x1,x2,x3,x4) weight: (/ 1 2) + x1 + x4 .(x1,x2) weight: (/ 3 2) + x1 + x2 #=(x1,x2) weight: 0 del❆1_.(x1,x2) weight: 0 Usable rules: { 4..7 } Removed DPs: #1 #4 #5 Number of SCCs: 0, DPs: 0, edges: 0 YES