I looked at the axioms and one of them was that there is only one absolute being ("A(x)") & then another axiom assumes that another existing entity (they call it "Y(x)") is equivalent to it. I think this is all trivially satisfied w/ the singleton domain so their axioms are essentially describing a set w/ one element.
Seems novel but if you lack the prerequisite mathematical training then you might not notice they're not really saying much.