ABSTRACT
You are sitting in your armchair, reading a book and listening to the radio. The announcer makes a comment, and this triggers a train of verbal mentations that pass through your head. One thought leads to another until you come to realize something, reach a conclusion, face a dead-end or simply halt. Whichever is the case your mental soliloquy has come to an end and you now feel that your head is clear. Thought sequences of this type are familiar to everyone. They consist of finite, ordered progressions of discrete phrase-like thought expressions, and they are characterized by having well-demarcated beginnings and ends; in general, the sequence is no more than half a dozen states long, although some sequences are much longer.
