Use foliage’s built-in variable declaration stack

src/translate/verify_properties.rs

@@ -371,7 +371,8 @@ fn read_rule(rule: &clingo::ast::Rule, context: &Context) -> Result<(), crate::E
 			let definitions = definitions.get_mut(&head_atom.predicate_declaration).unwrap();
 
 			let head_atom_parameters = std::rc::Rc::clone(&definitions.head_atom_parameters);
-			context.variable_declaration_stack.borrow_mut().push(head_atom_parameters);
+			let variable_declaration_stack_guard = foliage::VariableDeclarationStack::push(
+				&context.variable_declaration_stack, head_atom_parameters);
 
 			let mut definition_arguments = translate_body(rule.body(), context)?;
 
@@ -401,7 +402,7 @@ fn read_rule(rule: &clingo::ast::Rule, context: &Context) -> Result<(), crate::E
 				definition_arguments.push(translated_head_term);
 			}
 
-			context.variable_declaration_stack.borrow_mut().pop()?;
+			drop(variable_declaration_stack_guard);
 
 			let free_variable_declarations = std::mem::replace(
 				&mut context.variable_declaration_stack.borrow_mut().free_variable_declarations,

src/translate/verify_properties/context.rs

@@ -22,7 +22,7 @@ pub(crate) struct Context
 
 	pub function_declarations: std::cell::RefCell<foliage::FunctionDeclarations>,
 	pub predicate_declarations: std::cell::RefCell<foliage::PredicateDeclarations>,
-	pub variable_declaration_stack: std::cell::RefCell<crate::VariableDeclarationStack>,
+	pub variable_declaration_stack: std::cell::RefCell<foliage::VariableDeclarationStack>,
 	pub variable_declaration_domains: std::cell::RefCell<VariableDeclarationDomains>,
 	pub program_variable_declaration_ids: std::cell::RefCell<VariableDeclarationIDs>,
 	pub integer_variable_declaration_ids: std::cell::RefCell<VariableDeclarationIDs>,
@@ -45,7 +45,7 @@ impl Context
 			function_declarations: std::cell::RefCell::new(foliage::FunctionDeclarations::new()),
 			predicate_declarations: std::cell::RefCell::new(foliage::PredicateDeclarations::new()),
 			variable_declaration_stack:
-				std::cell::RefCell::new(crate::VariableDeclarationStack::new()),
+				std::cell::RefCell::new(foliage::VariableDeclarationStack::new()),
 			variable_declaration_domains:
 				std::cell::RefCell::new(VariableDeclarationDomains::new()),
 			program_variable_declaration_ids: