Log Message:-----------Fix typo in math function docs, spotted by Heikki.
Modified Files:-------------- pgsql/doc/src/sgml: func.sgml (r1.508 -> r1.509) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.508&r2=1.509)