Re: Multiplication by 0: non-zero in versions 8 and 9

*To*: mathgroup at smc.vnet.net*Subject*: [mg131182] Re: Multiplication by 0: non-zero in versions 8 and 9*From*: Richard Fateman <fateman at cs.berkeley.edu>*Date*: Sun, 16 Jun 2013 05:16:35 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <kph7t1$2es$1@smc.vnet.net>

On 6/15/2013 1:16 AM, Sotirios Bonanos wrote: > Hello , > > I have noticed that in all Mathematica versions <8, multiplying a > real or complex number by the integer 0 gives 0, but in versions 8 > and 9 > > Times[0, 0.567] gives 0. > > and > > Times[1.23 + I 2.45, 0] gives 0. + 0. I > > I don't know what prompted this change but it is definitely wrong: > the zero property of multiplication holds for real and complex > numbers also (see > https://en.wikipedia.org/wiki/Multiplication#Properties) . > > Sotirios Bonanos http://www.inp.demokritos.gr/~sbonano/ > > You appear to be making a distinction between "0" and "0." and "0.+0.I". Yet for Mathematica, 0==0.+0.*I returns True. You may have a valid objection to something that has been changed in the program, but appealing to the wikipedia article is not particularly significant. After all, Times[0,x] comes out as 0, but this is not what happens for x being 0., Indeterminate, Infinity, Interval[{-1,1}], and probably other stuff. As Dorothy said, you are not in Kansas anymore. http://en.wiktionary.org/wiki/not_in_Kansas_anymore