Thank you, @jastey, that was so helpful . Some questions:
What is the format of dialogue state names?
What language is this? I think I read somewhere that IE scripts are based on a funny scripting language developed in a Brazilian university.
this is the conditions for which this state is called
What conditions can be used to call a dialogue state? What is the purpose of calling a dialogue state?
either PC reply options or other so called "transactions", i.e. actions that will be performed after the NPC line when the player clikcs on "CONTINUE".
What kinds of transactions exist?