All bets are off (anything goes) if _. is an argument to a function (other than 128!:5).
0=0*_ __ preserves the identity that 0*x=0 for any x . See also http://arxiv.org/PS_cache/math/pdf/9205/9205211v1.pdf in particular the discussion on "very strong 0" after equation 1.19 on page 8. ----- Original Message ----- From: "Leigh J. Halliwell" <[email protected]> Date: Tuesday, March 10, 2009 9:06 Subject: [Jprogramming] Multiplication Conventions To: 'Programming forum' <[email protected]> > Dear J Forum: > > Here is a multiplication table for multiplying with 0, plus or minus > infinity, and indeterminate: > > */ ~ x =. 0 _ __ _. > > 0 0 0 0 > 0 _ __ 0 > 0 __ _ 0 > 0 0 0 0 > > Is there a good reason why 0*_ = 0, rather than _.? And > why is _.* any = 0? > In particular, it seems to me that 0*_. should be zero, and that _.*_. > should be indeterminate. I'm just curious, especially > since I know the > reasons for the decision for 0%0 to equal 0. Thanks. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
