prolog to solve grammar involving braces
I'm trying to solve DCG grammar in prolog and succeeded upto a point, i'm stuck in evaluating the expressions involving braces like these. 

expr( T, [’(’, 5, +, 4, ’)’, *, 7], []),


    expr(Z) --> num(Z).
    expr(Z) --> num(X), [+], expr(Y), {Z is X+Y}.
    expr(Z) --> num(X), [-], expr(Y), {Z is X-Y}.
    expr(Z) --> num(X), [*], expr(Y), {Z is X*Y}.
    num(D) --> [D], {number(D)}.
    
    
    eval(L, V, []) :- expr(V, L, []).





prolog to solve grammar involving braces
===

I'm trying to solve DCG grammar in prolog and succeeded upto a point, i'm stuck in evaluating the expressions involving braces like these. 

expr( T, [’(’, 5, +, 4, ’)’, *, 7], []),


    expr(Z) --> num(Z).
    expr(Z) --> num(X), [+], expr(Y), {Z is X+Y}.
    expr(Z) --> num(X), [-], expr(Y), {Z is X-Y}.
    expr(Z) --> num(X), [*], expr(Y), {Z is X*Y}.
    num(D) --> [D], {number(D)}.
    
    
    eval(L, V, []) :- expr(V, L, []).




