Robert, I'm not a methematician either. What I wrote above is what's left from high school. That was 40 years ago. Purists may find minor flaws, but I think basically it should still be valid.

In an equation, an unknown is a number that is not known yet but has to be found. An indeterminate number cannot be found, because it is - uh - indeterminate. It can be any number.

Let me give you two examples:

1) You have five apples. Jack says he has twice as many, but won't tell you how many he has. It's up to you. The number of Jack's apples is the unknown, and if he isn't lying, it's possible for you to solve the equation.

2) Jill's legs are shorter than yours. Her pace is 9/10 of yours. When you and Jill take the same number N of steps, she will always be your pace x N x 0.9 behind you. It doesn't matter how many steps you take, it may be one or gazillions, the formula always gives you her lag in relation to your pace. Here, N is not unknown, it's just indeterminate; you can take any number you like.

By the way, in math(s), the term 'indeterminate' can be used in yet another sense, but I think that would go beyond the scope of this discussion.

Ken, I agree with you. I wrote "half-educated hacks" after having googled "R. H. Forude" to no avail; "Forude" yielded many hits, most of them Scandinavian pages not dealing with English names, let alone writers. I eventually gave up without finding the guy you mentioned. So I concluded that he probably wasn't a very outstanding figure, which may be wrong. Sorry about my lack of knowledge in that field.

**Reply from Hans Joerg Rothenberger (Walenstadt - Switzerland)**