Incremental processing and infinite local ambiguity

In incremental parsing, infinite local ambiguity occurs when the input word can be combined with the syntactic structure built so far in a infinite number of ways. A common example is left recursion(e.g. "railway station clock" or "his sister's boyfriend's shirt"), where local information cannot tell us the depth of embedding of the left descendent chain of nodes. From the processing point of view, infinite local ambiguity causes a technical problem, which a model must solve in order to implement incrementality fully. This paper provides a general solution to the problem of infinite local ambiguity, by introducing the concept of Minimal Recursive Structure. We give two examples of parsers in which the solution is used.