Gittin 84: Absurd Conditions for Divorce

More other conditions that a husband might stipulate in a bill of divorce - for example, if he stipulates that she now marry another specific man -- then the divorce will take effect. But does that work? Or what if the condition is something that isn't humanly possible? Or on condition that she do a sin against the Torah? Also, what about when the condition is written into the get? Isn't that automatically a problem? It may actually depend on where in the get it's written (or said, for that matter) -- namely, it has to be stipulated after the "toref" of the get - the part with the people's names and the date and so on.