Constraints/Triggers information?

I've got a snipped script like thus:

---------------------------------------------------
alter table license drop constraint fk_lic_lc restrict ;
drop table license ;
create table license (
  id numeric(18),
 . . .
) ;
alter table license add constraint fk_lic_lc
  foreign key (license_code_id) references license_code (id) ;
---------------------------------------------------

Where the final statement had previously run successfully:

---------------------------------------------------
psql:file.sql:284: NOTICE:
  ALTER TABLE will create implicit trigger(s) for FOREIGN KEY check(s)
---------------------------------------------------

The initial statement (alter table drop constraint) always fails with

---------------------------------------------------
psql:file.sql:22: ERROR:  ALTER TABLE / DROP CONSTRAINT:
  fk_lic_lc does not exist
---------------------------------------------------

I can find nothing in psql's "\?" that talks about either triggers or
referential integrity constraints. Doing a "\d license" shows me several
RI entries like thus:

---------------------------------------------------
Triggers: RI_ConstraintTrigger_5602314,
          RI_ConstraintTrigger_5602320,
          RI_ConstraintTrigger_5602326
---------------------------------------------------

But I can't get any information on the RI_ entries. What's wrong with me?
Do I need to RTFM? If so, which FM do I need to R?

--
Tim Ellis
DBA, Gamet

ps -- doing drop constraint with cascade keyword gives me:
---------------------------------------------------
psql:file.sql:22: ERROR:  ALTER TABLE / DROP CONSTRAINT
  does not support the CASCADE keyword
---------------------------------------------------