<HTML>>>It is generally not >>necessary to give mode declarations for _functions_ since, if no mode >>declaration is given, a default mode is assumed where every argument >>has mode 'in', the result has mode 'out' and the determinism is 'det'. As a neophyte writing code, being explicit with the modes kind of helped me see the consitency between functions and predicates. I went ahead and stripped them out of the example on the web page, which does help shorten the code up and improve readability a tad. Thanks.</HTML>