diff --git a/src/format/formulas.rs b/src/format/formulas.rs
index ed6364d..a6f0965 100644
--- a/src/format/formulas.rs
+++ b/src/format/formulas.rs
@@ -47,7 +47,7 @@ fn requires_parentheses<'formula>(formula: &'formula crate::Formula,
 		Formula::And(formulas)
 		| Formula::Or(formulas) if formulas.len() <= 1
 			=> false,
-		Formula::And(formulas) => match *parent_formula
+		Formula::And(_) => match *parent_formula
 		{
 			Formula::Not(_)
 			| Formula::Exists(_)
@@ -55,7 +55,7 @@ fn requires_parentheses<'formula>(formula: &'formula crate::Formula,
 				=> true,
 			_ => false,
 		},
-		Formula::Or(formulas) => match *parent_formula
+		Formula::Or(_) => match *parent_formula
 		{
 			Formula::Not(_)
 			| Formula::Exists(_)
@@ -86,7 +86,7 @@ fn requires_parentheses<'formula>(formula: &'formula crate::Formula,
 				},
 			_ => false,
 		},
-		Formula::IfAndOnlyIf(formulas) => match *parent_formula
+		Formula::IfAndOnlyIf(_) => match *parent_formula
 		{
 			Formula::Not(_)
 			| Formula::Exists(_)
@@ -96,7 +96,6 @@ fn requires_parentheses<'formula>(formula: &'formula crate::Formula,
 				=> true,
 			_ => false,
 		},
-		_ => true,
 	}
 }