e7

unix v7是最后一个广泛发布的研究型UNIX版本

.NH
Conclusions
.PP
We think we have shown that it is possible
to do acceptably good typesetting of mathematics
on a phototypesetter,
with an input language that is easy to learn and use and
that satisfies many users' demands.
Such a package can be implemented in
short order,
given a compiler-compiler and
a decent typesetting program underneath.
.PP
Defining a language, and building a compiler for it
with a compiler-compiler
seems like the only sensible way to do business.
Our experience with the use of
a grammar and a compiler-compiler has been
uniformly favorable.
If we had written everything into code directly,
we would have been locked into
our original design.
Furthermore, we would have never been sure
where the exceptions and special cases were.
But because we have a grammar, we can change our minds readily and still be reasonably
sure that if a construction works in one place
it will work everywhere.
.SH
Acknowledgements
.PP
We are deeply indebted to
J. F. Ossanna,
the author of
.UC TROFF ,
for his willingness to modify
.UC TROFF
to make our task easier
and for his continuous assistance
during the development of our program.
We are also grateful to
A. V. Aho for help with language theory,
to S. C. Johnson for aid with the compiler-compiler,
and to our early users
A. V. Aho, S. I. Feldman, S. C. Johnson,
R. W. Hamming,
and M. D. McIlroy
for their constructive criticisms.
.SH
References
.IP [1]
.ul
A Manual of Style,
12th Edition.
University of Chicago Press, 1969. p 295.
.IP [2]
.ul
Model C/A/T Phototypesetter.
Graphic Systems, Inc.,
Hudson, N. H.
.IP [3]
Ritchie, D. M., and Thompson, K. L.,
``The UNIX time-sharing system.''
\fIComm. ACM 17,\fR 7 (July 1974), 365-375.
.IP [4]
Ossanna, J. F.,
TROFF User's Manual.
Bell Laboratories Computing Science Technical Report 54, 1977.
.IP [5]
Aho, A. V., and Johnson, S. C.,
``LR Parsing.''
\fIComp. Surv. 6,\fR 2 (June 1974), 99-124.
.br
.IP [6]
B. W. Kernighan and D. M. Ritchie,
.ul
The C Programming Language.
Prentice-Hall, Inc., 1978.