From: "John Nall" Sent: Tuesday, April 04, 2006 8:05 PM > Generally speaking, the interval [1-9] is considered to be inclusive, > and [1,9] would just be those two values. [1-3,6} would be the > inclusive interval from 1 to 3, and also 6. This is the Unix convention. Mathematically speaking [1,9] is the closed interval from 1 to 9. It cotains all values of your domain in that range including the two listed. (1,9) is the open interval from 1 to 9. It contains all values of your domain in that range not including the two listed. Since we're dealing with the natural numbers, [2,8] = (1, 9), but it gets more interesting with reals. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist