1 CREATE 
2? OR REPLACE
3 FUNCTION function-name (
4? 
4+ ,
4 parameter-declaration
5 ) RETURNS  data-type2
6 option-list
7? SET OPTION-statement
8 SQL-routine-body

parameter-declaration

1 parameter-name data-type1

data-type

1 built-in-type
1 distinct-type-name