(* we ignore worlds *)
assignment * store -> 'a * assignment * store
- Although we're leaving worlds out of the picture, each of these monadic values still represents a different discourse possibility: which entities might be being talked about, using which variables.
+ Although we're leaving worlds out of the picture, each of these monadic values still represents a different *discourse* possibility: which entities might be being talked about, using which variables.
Since `dpm`s are to be a monad, we have to define a unit and a bind. These are just modeled on the unit and bind for the state monad: