  We consider a fair division model in which agents have positive, zero and
negative utilities for items. For this model, we analyse one existing fairness
property - EFX - and three new and related properties - EFX$_0$, EFX$^3$ and
EF1$^3$ - in combination with Pareto-optimality. With general utilities, we
give a modified version of an existing algorithm for computing an EF1$^3$
allocation. With $-\alpha/0/\alpha$ utilities, this algorithm returns an
EFX$^3$ and PO allocation. With absolute identical utilities, we give a new
algorithm for an EFX and PO allocation. With $-\alpha/0/\beta$ utilities, this
algorithm also returns such an allocation. We report some new impossibility
results as well.
