Where can I get a copy of this booklet? You can pick up a copy of this booklet at the Iverson Software booth.

What’s the purpose of this booklet? This booklet should allow you to explore some of the aspects of J in a fairly painless way. If you take it with you to a computer that has J installed you will find that the examples are short and easy to key in. The computers at the Iverson Software booth have a script file called APL93 that can be read in to define most of the objects used in this booklet.

Why “At work and play”? Most of us have to work for a living, and to that extent could be categorized as ants. I’ve always found it helpful to keep as much of the grasshopper as possible about me in the various jobs I’ve had, and love to look at the lighter side of work. For years I’ve been enchanted by the beauties of APL and now find myself even more so by J. The page headed Now, be rational is an example of what I mean. I had written a paper for APL75 suggesting the extension of the domain of the “and” and “or” functions to arbitrary numbers, where they would take the meaning of “lcm” “gcd”. Years later I implemented this extension for I.P. Sharp Associates’ APL system. It had only been released for a few hours when a message arrived from somewhere in western Canada describing this lovely way to obtain a rational approximation to a real number, using gcd. I took this as confirmation of the correctness of my suggestion, although I had not anticipated this extraordinary dividend. It is the “beauty bare” that Millay said only Euclid had looked on.

Thanks. Many of these pages contain work originated by Roger Hui or Ken Iverson. The tables on the No end in sight and Looking backward pages are due to Roger. The rows and columns for 0 in these tables supply ample confirmation of the decision to make 0 divided by 0 equal to 0 in J. To Roger also are due to the recursions on the Nifty combos page. Ken provided much of the material on the Another fine fix and Have a fit and More power to you and In such a fix to be so fertile pages. David Steinbrook supplied the incentive for most of the material on The long and the short of it page.