Fix negation parser

src/parse/formulas.rs

@@ -52,6 +52,8 @@ pub fn predicate<'i>(i: &'i str, d: &Declarations) -> IResult<&'i str, crate::Pr
 
 fn not<'a>(i: &'a str, d: &Declarations) -> IResult<&'a str, crate::Formula>
 {
+	map
+	(
 		preceded
 		(
 			terminated
@@ -60,6 +62,8 @@ fn not<'a>(i: &'a str, d: &Declarations) -> IResult<&'a str, crate::Formula>
 				multispace0,
 			),
 			|i| formula_precedence_2(i, d),
+		),
+		|x| crate::Formula::not(Box::new(x)),
 	)(i)
 }