How does it work?

Relplot recursively subdivides the plane using interval arithmetic to test for the possible presence of solutions to equations. One it has divided finely enough, it searches for solutions along the edges of each minimum-sized square, and draws line segments to connect solution points it finds.

Can I put in TeX formulas?

No, sorry. However, the syntax accepted by Relplot is very concise.

What is the difference between a*b and ab?

Multiplication written using juxtaposition (ab) has higher precedence. For example, sin 2*x is the same as (sin 2) * x, whereas sin 2x is the same as sin(2x).

How can I get a copy of the source code?

First, install Standard ML of New Jersey. Then, send me (Andrew Myers) an email request.