ORA-00920 error: invalid relational operator

Hello,

I have an SQL query for which I have the error above but I don't understand what is wrong.

Here is the query:

"select g.idcy00 as Company, f.lboulg as Department, H.nmpres as Manager, a.matcle, a.nomuse, a.prenom, i.acquia as Acquired, i.drtpri as Taken, (i.ajust1+i.ajust2+i.ajust3+i.ajust4) as Adjustment, i.restan as Balance
from zy3c b, ze00 c, ze2a d, ze00 e, ze01 f, zyes g, zydv i, zy00 a
left join zy3e h on a.nudoss = h.nudoss
where a.nudoss = b.nudoss and b.dten00 >= sysdate
and ((b.idou00 = c.idou00 and exists(select nudoss from zy3c where dten00 >= sysdate and TYTRST = 'FUN' and nudoss = a.nudoss) and b.TYTRST = 'FUN')
or
(b.idou00 = c.idou00 and not exists(select nudoss from zy3c where dten00 >= sysdate and TYTRST = 'FUN' and nudoss = a.nudoss) and b.TYTRST = 'HIE'))
and c.nudoss = d.nudoss and e.idou00 = d.idou01 and e.nudoss = f.nudoss and a.nudoss = i.nudoss and g.datsor >= '31/01/2019'
and a.nudoss = g.nudoss and g.datsor > sysdate and i.annees='01-01-2019' and i.codcon ='RTT'
and g.idcy00 in ('268','269')
and d.nbordr = (select max(nbordr)-1 from ze2a where ze2a.nudoss = d.nudoss) order by h.nmpres, f.lboulg, a.nomuse "

And what it doesn't like is the "=" here "and ((b.idou00 = c.idou00 and exists"

Could someone tell me what is wrong with my query??

Thank you in advance ;-)

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