People who fly, pay taxes, or use computers naturally feel unhappy about glitches and gremlins in critical systems. On the other hand, Bill Gates became the richest man on the planet by selling products that do not work correctly.
Maple sometimes mishandles the signum function.
This example is motivated by a query that Robert Ferreol posted to the Maple User Group mailing list on 18 June 1998. This is a modification of an example posted to the Maple User Group mailing list by Robert Israel in response to a question from David Lutterkort . If a linear algebra student were to give Maple the following commands, then you might say that this is not an intelligent thing to do. But even so, the student really would not deserve to be told by Maple that a square matrix has simultaneously maximal rank and a determinant equal to zero. The Math 696 course pages were last modified September 19, 2001.