Depending on the definition of "nontrivial", 3 more examples: range=: >. - <. 5 range 8 3 5 range _8.2 13.2
equal=: >. = <. 3 equal 4 0 3 equal _5.1 3 400.5 0 1 0 sgn=: > - < 3 sgn 4 _1 3 sgn 3 0 3 sgn _2 1 x sgn y is _1, 0, or 1, depending on whether x is less than, equal to, or greater than y. The monad * on real arguments is sgn&0 . ----- Original Message ----- From: Roger Hui <[email protected]> Date: Sunday, February 1, 2009 19:39 Subject: Re: [Jprogramming] Examples of dyadic forks To: Programming forum <[email protected]> > The following expresses the tautology that > ((x^2)-y^2) = (x+y)*(x-y) : > > diffsq=: -&*: = + * - > x=: 0.001 * _1e9 + 10 ?...@$ 2e9 > y=: 0.001 * _1e9 + 10 ?...@$ 2e9 > x diffsq y > 1 1 1 1 1 1 1 1 1 1 > > Your question brings to mind events in the early days of J. > For a time Ken wondered, are there many examples of fork? > After a while, it seemed that _everything_ was a fork. > http://keiapl.org/rhui/remember.htm#fork3 > > > > ----- Original Message ----- > From: John Randall <[email protected]> > Date: Sunday, February 1, 2009 15:21 > Subject: [Jprogramming] Examples of dyadic forks > To: JProgramming <[email protected]> > > > Does anyone have a good example of a dyadic fork? By this > > I mean one > > of the form fgh where f and g both use x and y, there are no [ > > or ], > > no constant functions, and no @ or @: . I am having > > trouble coming up > > with nontrivial examples. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
