usr/src/usr.bin/yacc/README

    Berkeley Yacc is an LALR(1) parser generator.  Berkeley Yacc has been
made as compatible as possible with AT&T Yacc.  Berkeley Yacc can accept
any input specification that conforms to the AT&T Yacc documentation.
Specifications that take advantage of undocumented features of AT&T Yacc
probably will be rejected.

    Berkeley Yacc is distributed with no warranty whatever.  Any program
of this size is almost certain to contain errors.  Neither the author nor
any contributor takes responsibility for any consequences of its use.

    Berkeley Yacc is in the public domain.  The data structures and
algorithms used in Berkeley Yacc were either taken from documents
available to the general public or were inventions of the author.
Anyone may freely distribute source or binary forms of Berkeley Yacc
whether unchanged or modified.  Distributors may charge whatever fees
they can obtain for Berkeley Yacc.  Programs generated by Berkeley Yacc
may be distributed freely.

    Please report bugs to

                          corbett@berkeley.edu

Include a small example if possible.  Please include the banner string from
skeleton.c with the bug report.  Do not expect rapid responses.