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bug alert!

  • To: mathgroup at
  • Subject: [mg25301] bug alert!
  • From: Jack Goldberg <jackgold at>
  • Date: Tue, 19 Sep 2000 03:45:22 -0400 (EDT)
  • Sender: owner-wri-mathgroup at

Hi group:

Brief report of a bug: ver 4.0x on  PowerMac and Unix systems.

Sum[ UnitStep[x-k],{k,0,Infinity} ] -> (1+x)*UnitStep[x]

which is incorrect.  The correct answer is  Floor[x]*UnitStep[x].
This error is compounded when you 


in that not only to you get an incorrect answer, the answer contains hidden
variables and is total nonsense.

Something is seriously at fault here. 

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