Bison is a general-purpose parser generator that converts a
 grammar description for an LALR(1) context-free grammar into a C
 program to parse that grammar. Once you are proficient with Bison, you
 may use it to develop a wide range of language parsers, from those used
 in simple desk calculators to complex programming languages.
 .
 This package provides the liby.a file including functions needed by
 yacc parsers.