RE: Formal Definition of the Term "Form"

*To*: mathgroup at smc.vnet.net*Subject*: [mg46158] RE: [mg46150] Formal Definition of the Term "Form"*From*: "David Park" <djmp at earthlink.net>*Date*: Mon, 9 Feb 2004 05:54:06 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Harold, I don't think there is a precise definition or usage of the term "form" in the Mathematica book. I think it depends on the context of the command. For example, in the Coefficient command in Section 1.4.7 it definitely does not work if form is a pattern. But in Section 2.3.2 with the Cases statement form usually is a pattern. And in the actual Help for Cases the word "pattern" instead of "form" is used. There are many places where The Book could probably be sharpened up. But it might threaten to make the book even longer! Help is probably a better guide in specific cases than the book. One place that the book could be improved is in discussing piecewise functions. UnitStep was only added to the main Mathematica with later versions. The book still tends to teach new users the conditional definition, If or Which constructions. I can't find an example in the main book where UnitStep is used to define a piecewise function. And the example in Help is slightly quixotic. As a result there are many questions about piecewise functions and calculus on MathGroup. The way you are going at Mathematica you are quickly becoming an expert! David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Harold Noffke [mailto:Harold.Noffke at wpafb.af.mil] To: mathgroup at smc.vnet.net MathGroup: In methodically reviewing everything I've read in the Mathematica Book, I realized an important undefined term first makes its appearance in "1.4.7 Picking Out Pieces of Algebraic Expressions". Definitions are there for Coefficient[expr,form] and Exponent[expr,form]. The term "expr" has been previously discussed, but the term "form" starts to be used at this point without any prior definition I can find. Does Mathematica have a formal definition for "form"? Where may I find it? Thanks. Harold