Question

我读了一个小时的代码，但我无法理解问题所在。我读到这个错误意味着我使用的参数我以前没有实例化，但我看不到它在哪里。你能帮助我吗？

as_monomial(X, m(X, 0, [])) :- number(X), !.
as_monomial(^(Y, Z), m(1, Z, [v(Z, Y)])) :- !.
as_monomial(*(X, ^(Y, Z)), m(G, K, Q)) :- as_monomial(X, m(G, TD, Vars)), K is (TD + Z), ordina_m([v(Z, Y)| Vars], Q), !.
as_monomial(*(X, Y), m(G, K, Q)) :- as_monomial(X, m(G, TD, Vars)), K is (TD + 1), ordina_m([v(1, Y)| Vars], Q), !.
as_monomial(-(X), m(-A, Y, L)) :- as_monomial(X, m(A, Y, L)).
as_monomial(X, m(1, 1, [v(1, X)])).

ordina_m(List, Sorted) :- sort(2, @=<, List,  Sorted).

ordina_poly1(List, Sorted) :- sort(2, @>=, List,  Sorted).
ordina_poly2(List, Sorted) :- sort(3, @=<, List,  Sorted).

is_monomial(m(_C, TD, VPs)) :- integer(TD), TD >= 0, is_list(VPs).
is_polynomial(poly(M)) :- is_list(M), foreach(member(Monomio, M), is_monomial(Monomio)).

as_polynomial(+(X, Y), poly(C)) :- as_monomial(Y, G), as_polynomial(X, poly(Gs)), inverti(G, H), inverti2(Gs, Hs), ordina_poly2([H| Hs], D), inverti2(D, F), ordina_poly1(F, C), !.
as_polynomial(-(X, Y), poly(C)) :- as_monomial(-Y, G), as_polynomial(X, poly(Gs)), inverti(G, H), inverti2(Gs, Hs), ordina_poly2([H| Hs], D), inverti2(D, F), ordina_poly1(F, C), !.
as_polynomial(X, poly([X])) :- is_monomial(X), !.
as_polynomial(X, poly([Q])) :- as_monomial(X, Q), !.

/* grado massimo */
maxdegree(Poly1, Result) :- is_polynomial(Poly1), max_degree(Poly1, Result), !.
maxdegree(Poly1, Result) :- as_polynomial(Poly1, Result1), max_degree(Result1, Result), !.

max_degree(poly([]), 0) :- !.
max_degree(poly([m(_, X, _)|Xs]), X) :- max_degree(poly(Xs), Ys), X > Ys, !.
max_degree(poly([m(_, X, _)|Xs]), Ys) :- max_degree(poly(Xs), Ys), X =< Ys, !.

/* grado minimo */
mindegree(Poly1, Result) :- is_polynomial(Poly1), min_degree(Poly1, Result), !.
mindegree(Poly1, Result) :- as_polynomial(Poly1, Result1), min_degree(Result1, Result), !.

min_degree(poly([m(_, X, _)]), X) :- !.
min_degree(poly([m(_, X, _)|Xs]), X) :- min_degree(poly(Xs), Ys), X < Ys, !.
min_degree(poly([m(_, X, _)|Xs]), Ys) :- min_degree(poly(Xs), Ys), X >= Ys, !.

inverti(m(_, _, []), m(_, _, [])) :- !.
inverti(m(X, Y, [v(W, Z)| Xs]), m(X, Y, [v(Z, W)| Ys])) :- inverti(m(X, Y, Xs), m(X, Y, Ys)), !.

inverti2([], []) :- !.
inverti2([m(X, Y, [])| Zs], [m(X, Y, [])| Ss]) :- inverti2(Zs, Ss), !.
inverti2([m(X, Y, [v(W, Z)| Xs])| Zs], [m(X, Y, [v(Z, W)| Ys])| Ss]) :- inverti2([m(X, Y, Xs)| Zs], [m(X, Y, Ys)| Ss]), !.

我不会包含as / is_polynomial cuz的代码我之前已经使用过它而且我对这段代码没有问题。你能帮我吗？我试过的一个例子是maxdegree（x ^ 5 + y ^ 500 + 4，R）。（对于mindegree来说同样的事情）

Answer 1

我解决了我的问题，在maxdegree和mindegree中添加了一个clausure作为基本案例：

max_degree(poly([m(_, _X, [])]), 0) :- !. max_degree(poly([m(_, X, _)]), X).

min_degree(poly([m(_, _X, [])]), 0) :- !. min_degree(poly([m(_, X, _)]), X) :- !.

参数实例化不充分

1 个答案: