init init_anamedargexpr (
		n_id: nullable TId,
		n_assign: nullable TAssign,
		n_expr: nullable AExpr
	)
	do
		_n_id = n_id.as(not null)
		n_id.parent = self
		_n_assign = n_assign.as(not null)
		n_assign.parent = self
		_n_expr = n_expr.as(not null)
		n_expr.parent = self
	end