DO
$do$
DECLARE
   arr varchar[] := '{"{key1,val1}","{key2,val2}","{key3,val3}","{key4,val4}"}';
BEGIN
   FOR i IN array_lower(arr, 1) .. array_upper(arr, 1)
   LOOP
   IF(((arr[i])::text[])[1]='key3')
   THEN
   arr:=array_remove(arr,arr[i]);
   END IF;
      RAISE NOTICE '% ) show(%,%)',i, (arr[i]::text[])[1], (arr[i]::text[])[2];
   END LOOP;
END
$do$

with vdata AS (
SELECT array_agg(i-1 order by i) apos
,array_agg(i+1 order by i) asym
FROM generate_series(0,1000,6) i 
)

SELECT foo.* 
FROM vdata 
,lateral
(SELECT s1.pos as pos1, s2.pos as pos2
FROM
(select pos,sym from unnest(apos ,asym) u(pos,sym) ) s1
INNER JOIN
(
select pos,sym from unnest(apos ,asym) u(pos,sym)) s2
ON s2.pos > s1.pos
WHERE (s1.sym = 37)  AND (s2.sym = 73)
) foo
--INTO var_pos1,var_pos2
;

with vdata AS (
SELECT
array_agg(array[i-1,i+1]::text order by i) apos_sym
FROM generate_series(0,1000,6) i 
)

SELECT foo.* 
FROM vdata 
,lateral
(SELECT s1.pos as pos1, s2.pos as pos2
FROM
(select (u::int[])[1] as pos,(u::int[])[2] as sym from unnest(apos_sym) u(u) ) s1
INNER JOIN
(select (u::int[])[1] as pos,(u::int[])[2] as sym from unnest(apos_sym) u(u) ) s2
ON s2.pos > s1.pos
WHERE (s1.sym = 37)  AND (s2.sym = 73)
) foo
--INTO var_pos1,var_pos2
;

with vdata AS (
SELECT
array_agg(array[i-1,i+1] order by i) apos_sym
FROM generate_series(0,1000,6) i 
)

SELECT foo.*
FROM vdata v
,lateral
(SELECT s1.pos as pos1, s2.pos as pos2
FROM
(select pos, apos_sym[u.ord/2+1][2] sym from unnest(apos_sym)
with ordinality u(pos, ord)
where u.ord % 2 = 1
) s1
INNER JOIN
(select pos, apos_sym[u.ord/2+1][2] sym from unnest(apos_sym)
with ordinality u(pos, ord)
where u.ord % 2 = 1
) s2
ON s2.pos > s1.pos
WHERE (s1.sym = 37)  AND (s2.sym = 73)
) foo
--INTO var_pos1,var_pos2
;

create type myarr as (f int[]);
with datas as (select array_agg( row(array[i,j,i+1,j+1])::myarr ) ag from generate_series(0,100) i,generate_series(0,100)j)
SELECT u.*,w, u.f[4] from datas ,lateral unnest(ag) u, lateral unnest(u.f) w