??hmm, so _is_ the stalk of the sheaf of open subspaces of a tdch space x at a point pof x a boolean algebra?? ??and if so then _is_ there some sort of "formalization" (wrt "geometric" doctrine, presumably...) of the concept of boolean algebra here?? ...

also, if so, is there a nice way to describe this boolean algebra directly in terms of the "point" of the corresponding boolean algebra('s spectrum) ?? ...

seems not boolean... ?? at non-isolated point, consider germ of its complement ... ??...