A zerofier tree is a balanced binary tree of vanishing polynomials.
Conceptually, every leaf corresponds to a single point, and the value of
that leaf is the monic linear polynomial that evaluates to zero there and
no-where else. Every non-leaf node is the product of its two children.
In practice, it makes sense to truncate the tree depth, in which case every
leaf contains a chunk of points whose size is upper-bounded and more or less
equal to some constant threshold.