Define DIALOGUE-NODE earlier.
Unnecessary, in light of how overall search is defined.
Initial formula.
Whitespace.
Ignore initial queue and node.
Read-only.
Read-only.
Read-only.
This is for DIALOGUE-NODE objects.
Revert to read-write slots.

It seems we have backed ourselves into a corner -- we need these slots
to be writable.
Assume that the action is set.
Already defined.
Dump old functionality.
Set the STATE slot of a dialogue if the action is known.
Set the INITIAL-NODE slot of a PROBLEM.
New.
Wrong function.
Ensure that EQ formulas aren't present.
Ensure that EQ formulas aren't present.
Attack negations.