pub fn sum_checker_x(
        p1: SepticCurve<F>,
        p2: SepticCurve<F>,
        p3: SepticCurve<F>,
    ) -> SepticExtension<F> {
        (p1.x.clone() + p2.x.clone() + p3.x) * (p2.x.clone() - p1.x.clone()).square() -
            (p2.y - p1.y).square()
    }
Given three points p1, p2, p3, the function is zero if and only if p3.x == (p1 + p2).x
assuming that no weierstrass edge cases occur.
crates/stark/src/septic_curve.rs