Re: Using a logical Or in the function definition

*To*: mathgroup at smc.vnet.net*Subject*: [mg86717] Re: Using a logical Or in the function definition*From*: Albert Retey <awnl at arcor.net>*Date*: Wed, 19 Mar 2008 05:25:27 -0500 (EST)*References*: <fro39q$i8a$1@smc.vnet.net>

Hi, > ab[ Or[r_Integer,r_Rational], Or[s_Integer,s_Rational] ]:=r/s; When constructing Patterns, you need to use Alternatives, not Or, which serves a different purpose. I think ab[r:(_Integer|_Rational),s:(_Integer|_Rational)]:=r/s should do what you need (| is a shortcut for Alternatives). If this is unfamiliar to you, you might consider learning more about pattern matching in mathmatica. hth, albert