YES TPA v.1.0 Result: TRS is terminating Default interpretations for symbols are not printed. For polynomial interpretations and semantic labelling over N\{0,1} defaults are 2 for constants, identity for unary symbols and x+y-2 for binary symbols. For semantic labelling over {0,1} (booleans) defaults are 0 for constants, identity for unary symbols and disjunction for binary symbols. [1] TRS loaded from input file: (1) plus(x,0) -> x (2) plus(x,s(y)) -> s(plus(x,y)) (3) times(0,y) -> 0 (4) times(x,0) -> 0 (5) times(s(x),y) -> plus(times(x,y),y) (6) p(s(s(x))) -> s(p(s(x))) (7) p(s(0)) -> 0 (8) fac(s(x)) -> times(fac(p(s(x))),s(x)) [2] Label this TRS using following interpretation over N\{0,1}: [s(x)] = x + 1 [times(x,y)] = (x-2)*(y-2) + 2 [p(x)] = max(2, x - 1) [fac(x)] = 2 rest default This interpretation is a model and yields following TRS: (1) plus{i,2}(x,0) -> x (2) plus{i,j + 1}(x,s{j}(y)) -> s{j + i - 2}(plus{i,j}(x,y)) (3) times{2,j}(0,y) -> 0 (4) times{i,2}(x,0) -> 0 (5) times{i + 1,j}(s{i}(x),y) -> plus{6 + i*j - 2j - 2i,j}(times{i,j}(x,y),y) (6) p{2 + i}(s{i + 1}(s{i}(x))) -> s{i}(p{i + 1}(s{i}(x))) (7) p{3}(s{2}(0)) -> 0 (8) fac{i + 1}(s{i}(x)) -> times{2,i + 1}(fac{i}(p{i + 1}(s{i}(x))),s{i}(x)) [3] All the rules of this TRS can be oriented with RPO with the following precedence: Status: plus: Lex-LR, times: Lex-LR, Precedence: plus{i,j} = plus{k,l} for all i, j, k, l plus{i,j} > s{k} for all i, j, k times{i,j} > plus{k,l} for all i, j, k, l p{i} > s{k} for all i, k times{i,j} = times{k,l} for all i, j, k, l fac{i} > times{k,l} for all i, k, l p{i} = p{k} for all i, k fac{i} > p{k} for all i, k fac{i} > fac{k} for i > k ../tpdb/TRS/AProVE/fac.trs, 0.01, Y Couldn't open file <60>: 60: No such file or directory