This is a type of hash table storing the output of a pseudowitness set computation using monodromy, with the following keys:
For a discussion of pseudowitness sets, see J.D. Hauenstein and A.J. Sommese, $Witness sets of projections$, Appl. Math. Comput. 217(7) (2010), 33493354.
The following example demonstrates the output for the degree $3$ embedding of $P^1$ into $P^3$, whose image is the twisted cubic.



The object PseudoWitnessSet is a type, with ancestor classes HashTable < Thing.