Added precedences

src/main/cup/chocopy/pa1/ChocoPy.cup

@@ -213,7 +213,6 @@ terminal String RBR;
 terminal String ARROW;
 terminal String IS;
 
-
 /* Returned by the lexer for erroneous tokens.  Since it does not appear in
  * the grammar, it indicates a syntax error. */
 terminal UNRECOGNIZED;   
@@ -231,7 +230,13 @@ non terminal Expr              expr, binary_expr;
 
 /* Precedences (lowest to highest) for resolving what would otherwise be
  * ambiguities in the form of shift/reduce conflicts.. */
-precedence left PLUS;
+precedence left OR;
+precedence left AND;
+precedence left NOT;
+precedence nonassoc EQUAL, NEQ, LT, GT, LEQ, GEQ, IS;
+precedence left PLUS, MINUS;
+precedence left MUL, DIV, MOD;
+precedence left DOT, COMMA, LBR, RBR;
 
 /* The start symbol. */
 start with program;