IDEA: clear a-z cmd

[cyrille de brébisson]

Hello,

One of the issue here is the meaning of the word "variable".

In symbolic math, a variable is a name used in replacement of an unknown value. In the symbolic word, a variable does not have any value (at least most of the time).

In lower grade math, in "computational" math, in physics or in programming worlds, a variable is a named container for a value. a Variable always has a value which it temporary replaces for clarity, readability or to allow a series of final computations with various values for the said variables.

Prime does have both these worlds in it. Home is definitely computational math. Cas is symbolic. But the 2 also interact to add to the confusion

The end result is Prime. Power and flexibility, but at the cost of the need to understand such subtility.

In your case, remember that by default, A-Z variables always have a value (computational) and a-z (lowercase) do not (symbolic). And you should be OK.

Hope this helps.

Cyrille