Postgres Array Bounds

.sql

CREATE OR REPLACE FUNCTION array_bounds(actual integer[], upper integer[], lower integer[]) RETURNS boolean
    AS $$
	DECLARE 
	length integer;
	BEGIN
		IF actual is NULL THEN
			RETURN FALSE;
		END IF;

		SELECT array_length(actual, 1) into length;
		

		
		IF length <> array_length(upper, 1) AND length <> array_length(upper, 1)
		THEN
			RETURN FALSE;
		ELSE
			FOR i IN 1 .. length
			LOOP
				IF actual[i] is null or actual[i] < lower[i] or actual[i] > upper[i] 
				THEN
					RETURN FALSE;
				END IF;
			END LOOP;
			RETURN TRUE;
		END IF;

		RETURN TRUE;
	END;	
    $$

    
    LANGUAGE plpgsql
    IMMUTABLE;