should Positive[ complexNumber ] return undefined instead of False?
- To: mathgroup at smc.vnet.net
- Subject: [mg112582] should Positive[ complexNumber ] return undefined instead of False?
- From: "Nasser M. Abbasi" <nma at 12000.org>
- Date: Tue, 21 Sep 2010 02:04:18 -0400 (EDT)
- Reply-to: nma at 12000.org
math experts: x = 3*I; Positive[x] Out[59]= False Should this be undefined or unevaluated? If it is False, when there must be an case when it is True, right? but there is not such case, positive and negative are not defined on the complex numbers, or Am I missing something? I know the above works as documented: "Positive[x] gives False if x is manifestly a negative numerical quantity, a complex numerical quantity, or zero. Otherwise, it remains unevaluated" So, my question is just wanting to know why when Mathematica was designed, the complexes were not added to the case where they remains unevaluated in this case? --Nasser
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