Incorrect type definition

[ascherer]

gb_words.w gets clobbered after section 23, because hash_prime gets treated as a type instead of as a value; see attached gb_words.pdf.

A temporary solution is

typedef Vertex @[*hash_table[hash_prime]@];

but, of course, we can't impose that on The Stanford GraphBase et al.

[texdraft]

This one is my fault. Production 117 should check for lbrack as well as lpar and exp and cast.

[ascherer]

@texdraft Thanks!