ENHANCED: use (+)/2 to express unary minus

This makes answers a bit shorter and more readable.

Example:

    ?- X #= -Y.
       clpz:(X+Y#=0).

This addresses #2058.

diff --git a/src/lib/clpz.pl b/src/lib/clpz.pl
index d4e59d45dd6cacb1368ab58940ef46fc3317e3b2..5e73a14feb5f6d1df674cdb0314fba9eef9b260a 100644 (file)
--- a/src/lib/clpz.pl
+++ b/src/lib/clpz.pl
@@ -2566,7 +2566,7 @@ parse_clpz(E, R,
              g(power_var_num(E, V, N)) => [p(pexp(V, N, R))],
              m(A*B)            => [p(ptimes(A, B, R))],
              m(A-B)            => [p(pplus(R,B,A))],
-             m(-A)             => [p(ptimes(-1,A,R))],
+             m(-A)             => [p(pplus(A,R,0))],
              m(max(A,B))       => [g(A #=< #R), g(B #=< R), p(pmax(A, B, R))],
              m(min(A,B))       => [g(A #>= #R), g(B #>= R), p(pmin(A, B, R))],
              m(A mod B)        => [g(B #\= 0), p(pmod(A, B, R))],
@@ -2824,7 +2824,7 @@ matches([
          m(var(X) #= var(Y)+var(Z)) => [p(pplus(Y,Z,X))],
          m(var(X) #= var(Y)-var(Z)) => [p(pplus(X,Z,Y))],
          m(var(X) #= var(Y)*var(Z)) => [p(ptimes(Y,Z,X))],
-         m(var(X) #= -var(Z))       => [p(ptimes(-1, Z, X))],
+         m(var(X) #= -var(Z))       => [p(pplus(X,Z,0))],
          m_c(any(X) #= any(Y), left_right_linsum_const(X, Y, Cs, Vs, S)) =>
             [g(scalar_product_(#=, Cs, Vs, S))],
          m_c(var(X) #= abs(var(Y)) + any(V0), X == Y) => [d(V0,V),p(x_eq_abs_plus_v(X,V))],
@@ -3560,7 +3560,7 @@ parse_reified(E, R, D,
                m(A+B)        => [d(D), p(pplus(A,B,R)), a(A,B,R)],
                m(A*B)        => [d(D), p(ptimes(A,B,R)), a(A,B,R)],
                m(A-B)        => [d(D), p(pplus(R,B,A)), a(A,B,R)],
-               m(-A)         => [d(D), p(ptimes(-1,A,R)), a(R)],
+               m(-A)         => [d(D), p(pplus(A,R,0)), a(R)],
                m(max(A,B))   => [d(D), p(pgeq(R, A)), p(pgeq(R, B)), p(pmax(A,B,R)), a(A,B,R)],
                m(min(A,B))   => [d(D), p(pgeq(A, R)), p(pgeq(B, R)), p(pmin(A,B,R)), a(A,B,R)],
                m(abs(A))     => [d(D), g(#R#>=0), p(pabs(A, R)), a(A,R)],