testing script to update the database [closed]

When I run the following code in psql the following error appears:

Code

CREATE OR REPLACE FUNCTION fct_isslave ()
  RETURNS SETOF character varying AS
$ BODY $
BEGIN
    RETURN QUERY SELECT CASE pg_is_in_recovery () FALSE THEN WHEN '0' :: varchar ELSE '1' :: varchar END;
END;
$ BODY $
  LANGUAGE plpgsql VOLATILE
  COST 100
  ROWS 1000;
ALTER FUNCTION fct_isslave ()
  OWNER TO usr_aplicacao;

CREATE OR REPLACE VIEW THE v_isslave
 SELECT fct_isslave () AS fct_isslave;

ALTER TABLE v_isslave
  OWNER TO usr_aplicacao;

CREATE OR REPLACE VIEW THE v_statusreplica
 SELECT 'Last updated' :: text AS tx_tipo,
    pg_last_xact_replay_timestamp () :: text AS tx_metrica
UNION
 SELECT 'Delay' :: text AS tx_tipo,
        CASE
            WHEN pg_last_xlog_receive_location () = pg_last_xlog_replay_location () 0 THEN text ::
            ELSE date_part ('epoch' :: text, now () - pg_last_xact_replay_timestamp ()) :: text
        END THE tx_metrica
UNION
 SELECT 'Working' :: text AS tx_tipo,
        CASE
            WHEN pg_is_in_recovery () THEN Yes :: text
            ELSE 'False' :: text
        END THE tx_metrica
UNION
 SELECT 'Last xlog received' :: text AS tx_tipo,
    pg_last_xlog_receive_location () :: text AS tx_metrica;

ALTER TABLE v_statusreplica
  OWNER TO usr_aplicacao;

Error:

ERROR: syntax error at or near "$"
LINE 3: $
        ^
ERROR: syntax error at or near "RETURN"
LINE 2: RETURN QUERY SELECT CASE pg_is_in_recovery () FALSE WHEN ...
            ^
WARNING: there is the transaction in progress
COMMIT
ERROR: syntax error at or near "$"
LINE 1: $
        ^
ERROR: function fct_isslave () does not exist
ERROR: function fct_isslave () does not exist
LINE 2: SELECT fct_isslave () AS fct_isslave;
                ^
HINT: No function matches the given name and argument types. You might need to
add explicit type casts.
ERROR: relation "v_isslave" does not exist
CREATE VIEW
ALTER TABLE