MAYBE * Step 1: WeightGap MAYBE + Considered Problem: - Strict TRS: add(0(),X) -> X add(s(X),Y) -> s(add(X,Y)) and(false(),Y) -> false() and(true(),X) -> X first(0(),X) -> nil() first(s(X),cons(Y,Z)) -> cons(Y,first(X,Z)) from(X) -> cons(X,from(s(X))) if(false(),X,Y) -> Y if(true(),X,Y) -> X - Signature: {add/2,and/2,first/2,from/1,if/3} / {0/0,cons/2,false/0,nil/0,s/1,true/0} - Obligation: innermost runtime complexity wrt. defined symbols {add,and,first,from,if} and constructors {0,cons,false,nil ,s,true} + Applied Processor: WeightGap {wgDimension = 1, wgDegree = 1, wgKind = Algebraic, wgUArgs = UArgs, wgOn = WgOnAny} + Details: The weightgap principle applies using the following nonconstant growth matrix-interpretation: We apply a matrix interpretation of kind constructor based matrix interpretation: The following argument positions are considered usable: uargs(cons) = {2}, uargs(s) = {1} Following symbols are considered usable: all TcT has computed the following interpretation: p(0) = [1] p(add) = [9] x1 + [2] x2 + [0] p(and) = [3] x1 + [2] x2 + [1] p(cons) = [1] x2 + [0] p(false) = [1] p(first) = [8] x1 + [8] p(from) = [1] p(if) = [2] x2 + [2] x3 + [4] p(nil) = [1] p(s) = [1] x1 + [1] p(true) = [0] Following rules are strictly oriented: add(0(),X) = [2] X + [9] > [1] X + [0] = X add(s(X),Y) = [9] X + [2] Y + [9] > [9] X + [2] Y + [1] = s(add(X,Y)) and(false(),Y) = [2] Y + [4] > [1] = false() and(true(),X) = [2] X + [1] > [1] X + [0] = X first(0(),X) = [16] > [1] = nil() first(s(X),cons(Y,Z)) = [8] X + [16] > [8] X + [8] = cons(Y,first(X,Z)) if(false(),X,Y) = [2] X + [2] Y + [4] > [1] Y + [0] = Y if(true(),X,Y) = [2] X + [2] Y + [4] > [1] X + [0] = X Following rules are (at-least) weakly oriented: from(X) = [1] >= [1] = cons(X,from(s(X))) Further, it can be verified that all rules not oriented are covered by the weightgap condition. * Step 2: Failure MAYBE + Considered Problem: - Strict TRS: from(X) -> cons(X,from(s(X))) - Weak TRS: add(0(),X) -> X add(s(X),Y) -> s(add(X,Y)) and(false(),Y) -> false() and(true(),X) -> X first(0(),X) -> nil() first(s(X),cons(Y,Z)) -> cons(Y,first(X,Z)) if(false(),X,Y) -> Y if(true(),X,Y) -> X - Signature: {add/2,and/2,first/2,from/1,if/3} / {0/0,cons/2,false/0,nil/0,s/1,true/0} - Obligation: innermost runtime complexity wrt. defined symbols {add,and,first,from,if} and constructors {0,cons,false,nil ,s,true} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE