A theory of ersatz impossible worlds is developed to deal with the problem of counterpossible conditionals. Using only tools standardly in the toolbox of possible worlds theorists, it is shown that we can construct a model for counterpossibles. This model is a natural extension of Lewis's semantics for counterfactuals, but instead of using classical logic as its base, it uses the logic LP.
"Who's Afraid of Impossible Worlds?." Notre Dame J. Formal Logic 38 (4) 516 - 526, Fall 1997. https://doi.org/10.1305/ndjfl/1039540767