The first example merely demonstrates that the left argument is a boolean 0 but the second is an integer 0.
In J, it is possible to generate (and distinguish) a "minus zero", but for the functions that matter (dyads = -: i. etc.) zero is the same as minus zero. It is possible to generate "minus zero" because I am unwilling to suffer the performance penalty in very common functions (times, divide, minus(?), etc.) that would be required to eradicate it. ----- Original Message ----- From: Jose Mario Quintana <[EMAIL PROTECTED]> Date: Monday, April 23, 2007 7:34 am Subject: RE: [Jgeneral] zero > > > Then again, the function 3!:3 can distinguish between 0 and -0, > > 0 ((-: ; ;)& (3!:3)) -0 > +-+--------+--------+ > |0|e1000000|e1000000| > | |01000000|04000000| > | |01000000|01000000| > | |00000000|00000000| > | |00000000|00000000| > +-+--------+--------+ > > although, > > 0 ((-: ; ;)& (3!:3)) _0 > +-+--------+--------+ > |1|e1000000|e1000000| > | |01000000|01000000| > | |01000000|01000000| > | |00000000|00000000| > | |00000000|00000000| > +-+--------+--------+ > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:general- > [EMAIL PROTECTED]> On Behalf Of Tracy Harms > > Sent: Tuesday, April 17, 2007 10:29 PM > > To: [email protected] > > Subject: [Jgeneral] zero > > > > Dan Bron wrote: > > > > > In J, 0 = -0 . The two values do not differ > > > and cannot be distinguished (A). So "(-0) is > > > the same as "0 . > > > > Zero has another property worth mentioning here: It > > sheds the negative sign. Consider statements such as > > those you make in your new essay, A Fine Line. For > > purposes of specifying rank, zero always has a > > continuity of properties with positive numbers, even > > if _0 is written. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
