Subject: Re: Numbers in Lisp (was: macros vs HOFs) From: Erik Naggum <erik@naggum.no> Date: 17 Sep 2002 13:53:24 +0000 Newsgroups: comp.lang.lisp Message-ID: <3241259604149116@naggum.no> * Alexander Schmolck <a.schmolck@gmx.net> | How does knowing that 'a' is of type rational completely determine the return | type of (sqrt a)? Please try to understand. The argument to `sqrt´ is of type `number´, and the return value is of type `number´. | What makes you think I disagree with this? Your repetitive argument about division. | I'm not. Sometimes, other people are better judges of such things than oneself. | I'm simply interested in the practical experiences [...] But you cannot do that usefully without understanding the theory. | I still think trying to draw from the practical expertise of other people is | often vastly superior to trying to derive something from first principles or | just adopting what is most common. Sure, but you need to understand fully what they have practical expertise in. | It is of course possible that what I want to know about is really to | imprecise or otherwise unsuitable to be properly answered in that way. It has appeared to me that you lack foundation in your quest for knowledge and thus that there is a high risk of leading you astray given truth that you will misinterpret. | If you mean of the first: (expt 27 1/3), (log 8 2) etc. I meant specifically the compatibility problems you alluded to. -- Erik Naggum, Oslo, Norway Act from reason, and failure makes you rethink and study harder. Act from faith, and failure makes you blame someone and push harder.