A course in logic by Girard...with
streaming video! And,
a paper by Patrick Girard, with the following abstract:
We present a generalization of Segerberg's onion semantics for belief
revision, in which the linearity of the spheres need not occur. The resulting
logic is called broccoli logic. We provide a minimal relational logic,
introducing a new neighborhood semantics operator. We then show that broccoli
logic is a well-known conditional logic, the Burgess-Veltman minimal conditional
logic.
which is of course blatant plagiarism from the appendix of "Locus Solum"!