Originally posted by Bardo

So... I´ve made three after triggers for each row in the table so if any row changes in the table, a procedure that makes a query to view what rows whith this special value are left in the table is fired.

This has generated an ORA-04091 error, alerting that the table must be mutating and my procedures/triggers may not view it.
This could be happening because you procedure is using DML statements that includes the table that fires the trigger.

If you wanna reference some value for a column in the row of the table that actually fires the trigger, you can use the ld and :new keywords to get it.

HTH