Subject: Mathematica 8 has conditional expressions
From: Richard Fateman
Date: Mon, 11 Jun 2012 18:03:49 -0700
For those interested in looking at a design, Mathematica 8
(parts are new in version 8....)
there are sections in the manual (which I think you can access
online without having a license) for
Procedural Conditionals
If - test if a condition is true, false, or of unknown truth value
Which - test which of a sequence of conditions are true
Switch - switch based on a value, with patterns allowed
Mathematical Function Conditionals
Piecewise - an arbitrary piecewise function
ConditionalExpression - expression defined under condition
UnitStep Sign Mod Floor Boole DiscreteIndicator ...
..................
Thus there is a separate version of a declarative conditional
for mathematical functions, different from "If".
Kind of like Maxima's prederror:false. Or something we
had in Tilu to return integration answers subject to conditions.
Oh, there is also a pattern-based conditional in Mathematica,
which is really "rules" for replace when a pattern matches (= condition,
I suppose).
Note also (maybe for Rich H.) the definition for piecewise
may be of interest.
RJF