hello Clay,

why not create it as:

CREATE DOMAIN LOGICAL
AS SMALLINT
DEFAULT 0 /* False */
NOT NULL
CHECK(VALUE IN (0, 1));

It is perfectly compatible with Delphi Boolean. Ah, don't use BOOLEAN as the
domain name because it seems to me that it is already a reserved word with
Interbase and it might become a reserved word in future versions of Firebird as
well.

Regards
Salvatore