PiecewiseExpand problem.

*To*: mathgroup at smc.vnet.net*Subject*: [mg84496] PiecewiseExpand problem.*From*: jackgold at umich.edu*Date*: Sat, 29 Dec 2007 20:00:48 -0500 (EST)

I am puzzled by the behavior of PiecewiseExpand. In its simplest version, my question is this: In 1: PiecewiseExpand[UnitStep[x]] Out 1: 1 x >= 0 Are we to assume from "Out 1" that UnitStep[x] for x < 0 is zero? And note the following: In 1: PiecewiseExpand[UnitStep[x],x < 0] Out 2: 0 By the way, PiecewiseExpand[UnitStep[x], -1 < x < 1] returns the same value as "Out 1". Jack