diff --git a/src/ast.rs b/src/ast.rs
index 3e9026b..95f632b 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -128,71 +128,6 @@ impl VariableDeclaration
 
 pub type VariableDeclarations = Vec<std::rc::Rc<VariableDeclaration>>;
 
-pub struct VariableDeclarationStack
-{
-	pub free_variable_declarations: VariableDeclarations,
-	bound_variable_declaration_stack: Vec<std::rc::Rc<VariableDeclarations>>,
-}
-
-impl VariableDeclarationStack
-{
-	pub fn new() -> Self
-	{
-		Self
-		{
-			free_variable_declarations: VariableDeclarations::new(),
-			bound_variable_declaration_stack: vec![],
-		}
-	}
-
-	pub fn find(&self, variable_name: &str) -> Option<std::rc::Rc<VariableDeclaration>>
-	{
-		for variable_declarations in self.bound_variable_declaration_stack.iter().rev()
-		{
-			if let Some(variable_declaration) = variable_declarations.iter().find(|x| x.name == variable_name)
-			{
-				return Some(std::rc::Rc::clone(&variable_declaration));
-			}
-		}
-
-		if let Some(variable_declaration) = self.free_variable_declarations.iter().find(|x| x.name == variable_name)
-		{
-			return Some(std::rc::Rc::clone(&variable_declaration));
-		}
-
-		None
-	}
-
-	pub fn find_or_create(&mut self, variable_name: &str) -> std::rc::Rc<VariableDeclaration>
-	{
-		if let Some(variable_declaration) = self.find(variable_name)
-		{
-			return variable_declaration;
-		}
-
-		let variable_declaration = VariableDeclaration
-		{
-			name: variable_name.to_owned(),
-		};
-		let variable_declaration = std::rc::Rc::new(variable_declaration);
-
-		self.free_variable_declarations.push(std::rc::Rc::clone(&variable_declaration));
-
-		variable_declaration
-	}
-
-	pub fn push(&mut self, bound_variable_declarations: std::rc::Rc<VariableDeclarations>)
-	{
-		self.bound_variable_declaration_stack.push(bound_variable_declarations);
-	}
-
-	pub fn pop(&mut self)
-	{
-		// TODO: return error instead
-		self.bound_variable_declaration_stack.pop().expect("bound variable is empty, cannot pop last element");
-	}
-}
-
 // Terms
 
 pub struct BinaryOperation