I am having second thoughts about the necessity of bifurcation. My first concern is the violence it does with the user input system: how does one specify multiple inputs in a menu? I am also motivated by the realization that roles may make bifurcation unnecessary. After all, if we clearly specify subject-roles for a series of verbs, bifurcation might well be possible.
The situation that demands bifurcation would require two responses to a single verb by a single character. Is this ever necessary? Or could the same thing be accomplished by a series of verbs? Can a branching structure always be replaced with a chain?
Two situations seem to demand branching: lies and deals. Let's examine each closely. In the case of lies, the branch arises at the moment the victim of the lie learns of the lie. The victim might want to do two things: deny the lie, and begin the attempt to track it down. Why could not these things be done in sequence? It would probably require that the reporter be shouldered aside, but I see little problem here; the same problem would exist if we had bifurcation.
Turning to the dealmaking structure, it seems easy to make it sequential. When the deal is agreed upon, each party sets up a consequence, one to carry out his side of the deal or renege, and the other to check in on whether the deal has been satisfied by a certain time. When that second party checks, the consequences are either to carry out/renege, or to remind the first party. Meanwhile, the first party sets up a similar dealcheck in response to carrying out his part of the bargain. All too easy.
I checked Laura's storyworld and found two locations that utilize bifurcation, both closely related. In each, a person who has been injured responds immediately with a counterattack, but also sets up a delayed check to see when s/he collapses from blood loss. Could this be handled with the chaining method? I believe so; it would merely be a matter of attaching another role to the immediate response for the deferred response.
My overall conclusion is that bifurcation is not necessary and should be dumped.