1. Re: 'Unknown' and three-valued logic
- Posted by Matthew Lewis <matthewwalkerlewis at YAHOO.COM> Nov 26, 2002
- 453 views
--- Rom <kjehas at frisurf.no> wrote: > |Example case: > |Simplified rules for unemployments benefits. How to program such > rules? > | > |To qualify for unemployment benefits.... > |1) you must be a national citizen > |2) you must be unemployed > |3) you must have earned more than $10000 previous year > |4) all facts must be documented (if you haven't supplied sufficient > domentation then employment office cannot make a positive decision) > > > All you get is check that the document has been submitted, if yes, > > then proceed, if no, then send them a leeter asking for more. I don't > > see anything hard in that. No 3-state needed... I think you have got > > uninitialised vcars and logic mixed up to much... > > Sorry, wrong answer. Even if sufficient documentation is not submitted, they > cannot say that you are not eligble for benefits. > The following program produces too many rejections, leading to a row of > complains...... Ok, fine, but that doesn't mean anything. The above example handles this perfectly, even though you provided a silly example. First, consider how you're getting the data. This can tell you whether you've got an unknown. Check one: Are you unemployed? Yes [ ] No [ ] etc. All you have to do is verify the input (which you should be doing anyways) and you'll know what extra information you need. Each exception could be added to a message. ("Need documentation of X. Your income exceeds the limit", etc). Why is this so hard? Matt Lewis __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com