New work with @aaron : https://ling.auf.net/lingbuzz/007450.

There's been debate recently about the discrete versus gradient nature of factive presuppositions ('Jo knows X' ~> X): specifically, whether factive predicates support inferences that are on a par with entailments, insofar as they are all-or-nothing - or something a bit weaker, giving rise to a boost to the likelihood that X is true without putting it on a par with other types of semantically licensed inference.