diff --git a/src/ast.rs b/src/ast.rs
index b212278..ed59891 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -70,12 +70,51 @@ impl PredicateDeclaration
 
 pub type PredicateDeclarations = std::collections::BTreeSet<std::rc::Rc<PredicateDeclaration>>;
 
-#[derive(Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct VariableDeclaration
 {
 	pub name: String,
 }
 
+impl std::cmp::PartialEq for VariableDeclaration
+{
+	#[inline(always)]
+	fn eq(&self, other: &VariableDeclaration) -> bool
+	{
+		let l = self as *const VariableDeclaration;
+		let r = other as *const VariableDeclaration;
+
+		l.eq(&r)
+	}
+}
+
+impl std::cmp::Eq for VariableDeclaration
+{
+}
+
+impl std::cmp::PartialOrd for VariableDeclaration
+{
+	#[inline(always)]
+	fn partial_cmp(&self, other: &VariableDeclaration) -> Option<std::cmp::Ordering>
+	{
+		let l = self as *const VariableDeclaration;
+		let r = other as *const VariableDeclaration;
+
+		l.partial_cmp(&r)
+	}
+}
+
+impl std::cmp::Ord for VariableDeclaration
+{
+	#[inline(always)]
+	fn cmp(&self, other: &VariableDeclaration) -> std::cmp::Ordering
+	{
+		let l = self as *const VariableDeclaration;
+		let r = other as *const VariableDeclaration;
+
+		l.cmp(&r)
+	}
+}
+
 impl VariableDeclaration
 {
 	pub fn new(name: String) -> Self