Module poly

Source
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Integer polynomials and exact real-root isolation.

Conic intersections lead to a quartic whose roots are nested radicals at best and not radicals at all in general (casus irreducibilis). So an exact root is represented the way CGAL’s Algebraic_kernel_d does it: a square-free integer polynomial plus a dyadic interval that contains exactly one of its roots. Every comparison is then decided exactly: by Sturm counts, by refining the intervals, or by a gcd when two roots might be equal.

Coefficients are BigInt. A polynomial with dyadic coefficients is scaled by a power of two first (IntPoly::from_dyadic), which does not move its roots.

Structs§

IntPoly
A polynomial with integer coefficients, lowest degree first, no trailing zeros (the zero polynomial is empty).
RealRoot
One real root of a square-free integer polynomial.