diff --git a/lib/pddlparse/include/pddlparse/AST.h b/lib/pddlparse/include/pddlparse/AST.h
index 7416b68..c7ce266 100644
--- a/lib/pddlparse/include/pddlparse/AST.h
+++ b/lib/pddlparse/include/pddlparse/AST.h
@@ -243,18 +243,6 @@ struct NAry
 	NAry &operator=(NAry &&other) = default;
 
 	Arguments arguments;
-
-	protected:
-		static Arguments copyArguments(const NAry<Derived, Argument> &other)
-		{
-			Arguments arguments;
-			arguments.reserve(other.arguments.size());
-
-			for (const auto &argument : other.arguments)
-				arguments.emplace_back(std::move(deepCopyVariant(argument)));
-
-			return arguments;
-		}
 };
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -330,11 +318,6 @@ struct Either: public NAry<Either<Argument>, Argument>
 	:	NAry<Either<Argument>, Argument>(std::move(arguments))
 	{
 	}
-
-	Either(const Either &other)
-	:	NAry<Either<Argument>, Argument>(this->copyArguments(other))
-	{
-	}
 };
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////