Note on using ternary plurality trees as a voting method having an efficient audit.
The TPT voting method arranges ballots at the leaves of a ternary tree. Each internal node computes a value (vote) that is the plurality vote of its three children. The value at the root is the winner of the contest.
An audit of a TPT contest outcome may require confirming that the relevant plurality nodes have correct values. In a typical case with only two candidates, the relevant nodes constitute a binary tree that is a proper subset of the overall ternary tree.
The method is described in a Jupyter notebook (TPT.ipynb) with executable Julia code.