This is an attempt at a naive implementation of Snelling's algorithm, ICS 1973.

Interpreter; obtains grammar and input as C code.

Corrections from the text have been marked by: /* text has: ... */

It is extremely unlikely that the algorithm can indeed do CF parsing in
O(n^2), but no refutation has been published to date; in fact, the paper does
not seem to be referenced anywhere.

The algorithm is described in reasonable detail, but not completely.  Filling
in the last details allows some examples in the paper to be reproduced, but
not all of them at the same time, it seems.  Further clarification would be
most welcome.