diff --git a/src/main/wacc/lexer.scala b/src/main/wacc/lexer.scala
index b1b1604..6b47b63 100644
--- a/src/main/wacc/lexer.scala
+++ b/src/main/wacc/lexer.scala
@@ -12,8 +12,6 @@ val errConfig = new ErrorConfig {
     "%" -> Label("binary operator"),
     "&&" -> Label("binary operator"),
     "*" -> Label("binary operator"),
-    "+" -> Label("binary operator"),
-    "-" -> Label("binary operator"),
     "/" -> Label("binary operator"),
     "<" -> Label("binary operator"),
     "<=" -> Label("binary operator"),
@@ -32,8 +30,8 @@ val errConfig = new ErrorConfig {
     "string" -> Label("valid type"),
     "fst" -> Label("pair extraction"),
     "snd" -> Label("pair extraction"),
-    "false" -> Label("boolean value"),
-    "true" -> Label("boolean value")
+    "false" -> Label("boolean literal"),
+    "true" -> Label("boolean literal")
   )
 }
 object lexer {
diff --git a/src/main/wacc/parser.scala b/src/main/wacc/parser.scala
index 5b8b06c..f4c0293 100644
--- a/src/main/wacc/parser.scala
+++ b/src/main/wacc/parser.scala
@@ -29,11 +29,14 @@ object parser {
         Greater from ">",
         GreaterEq from ">="
       ) +:
-      SOps(InfixL)(Add from "+", Sub from "-") +:
+      SOps(InfixL)(
+        (Add from "+").label("binary operator"),
+        (Sub from "-").label("binary operator")
+      ) +:
       SOps(InfixL)(Mul from "*", Div from "/", Mod from "%") +:
       SOps(Prefix)(
         Not from "!",
-        Negate from (notFollowedBy(negateCheck) ~> "-"),
+        (Negate from (notFollowedBy(negateCheck) ~> "-")).hide,
         Len from "len",
         Ord from "ord",
         Chr from "chr"
@@ -43,10 +46,10 @@ object parser {
 
   // Atoms
   private lazy val `<atom>`: Atoms[Expr6] = Atoms(
-    IntLiter(integer),
-    BoolLiter(("true" as true) | ("false" as false)),
-    CharLiter(charLit),
-    StrLiter(stringLit),
+    IntLiter(integer).label("integer literal"),
+    BoolLiter(("true" as true) | ("false" as false)).label("boolean literal"),
+    CharLiter(charLit).label("character literal"),
+    StrLiter(stringLit).label("string literal"),
     PairLiter from "null",
     `<ident-or-array-elem>`,
     Parens("(" ~> `<expr>` <~ ")")