I've been trying to create a problem that involves similar concepts as straightedge and compass construction.
The idea is to add a new tool that allows for a different type of graph to be drawn besides circles and lines, and then to ask whether previously impossible constructions such as squaring the circle or trisecting the angle have become possible (using the new tool).
Sadly, I haven't been able to find another kind of function (ellipses excluded) such that when one of its variables $x$ or $y$ is isolated and plugged in into another function of the same kind a polynomial is formed.
To be more specific, what I'm looking for is a function $f$ of two variables such that if
$$y-k=f(x-h, r)$$ and $$y-p=f(x-q, s)$$
then $$f(x-h, r)+k-f(x-q, s)-q = P(x) = 0$$
for some polynomial $P(x)$ with coefficients in $ℚ(k, h, p, q)$
The function doesn't have to form polynomials when the same process is followed but its variables are instead plugged in the equation of a line or a circle.
In such case one could simply not allow the use of compass and straightedge to draw circles and lines respectively, yet still ponder if some constructions have become possible.
I would really appreciate any help/thoughts