-- Note: incorrect module name
DECLARE EXTERNAL FUNCTION div
    INTEGER, INTEGER
    RETURNS DOUBLE PRECISION BY VALUE
    ENTRY_POINT 'IB_UDF_div' MODULE_NAME 'ib_udfx';

-- Error is ok
select div(2, 1) from rdb$database;

drop external function div;

-- Typo corrected
DECLARE EXTERNAL FUNCTION div
    INTEGER, INTEGER
    RETURNS DOUBLE PRECISION BY VALUE
    ENTRY_POINT 'IB_UDF_div' MODULE_NAME 'ib_udf';

-- Error remains
select div(2, 1) from rdb$database;