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From: david@cs.uq.oz.au (David Duke)
Newsgroups: comp.specification.z
Subject: Re: Prove me wrong
Message-ID: <2232@uqcspe.cs.uq.oz.au>
Date: 30 Jun 91 23:43:36 GMT
References: <1991Jun28.175058.4987@agate.berkeley.edu>
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Reply-To: david@cs.uq.oz.au
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In <1991Jun28.175058.4987@agate.berkeley.edu> bks@lima.berkeley.edu (Bradley K. Sherman) writes:


>Z will never emerge as a useful tool for real-world programmers and
>analysts because it cannot be expressed on glass tty's.

Oh?	\begin{schema}{table}
	   data : Key \ffun Value		\\
	   keys : \fset Key			\\
	\ST
	   \dom data = keys
	\end{schema}				
	
	:-) :-)

Seriously though, using the fuzz or oz macros with LaTeX, Z is not all
that unreadable.  It is also not to difficult to come up with ascii
`lookalikes' for many of the symbols in the standard library; I often
use such approximations when sending questions involving Z text by mail.
e.g.
	\dom	==> dom
	\tfun	==> ->
	\pfun	==> +>
	\ffun	==> ++>
	\dres	==> <|
	\limg	==> (|
	etc

Perhaps someone has proposed a a standard set of these?
The variety of box notations is more of a problem, but perhaps you could
use just the latex \begin{...} and \end{...} delimiters?

>Back to the drawing board and come up with an unambiguous syntax
>expressible in the intersection of the ASCII and EBCDIC codes
>and we can make some progress.

Whats ambiguous about the syntax?  There are several type checkers available
for Z (for example, `Fuzz' by Mike Spivey at the PRG, Oxford Uni); there is
also a syntax-based editor at UQ -- all of which need a precise syntax on
which to work!

>We just don't have the time to muck with Troff or Latex just to write
>down our specs for the systems.  Also we'd like to see the specs online.

Do you mean you don't have time to install/learn LaTeX, or you find it
too difficult to write Z specs *in* LaTeX; is the latter, have you looked
at the macro packages zed.sty and oz.sty?

>Is this too much to ask?

IMHO, the concise notation is one of the attractions of Z, and part of the
attraction is the use of standard mathematical symbols -- yes, there are
some peculiar to Z, but I did not find them hard to learn once you note
their regularity.  Replacing these with ascii equivalents may help those
with acess only to ascii terminals, but I don't think that this would
suddenly make it more popular or accessible.


>----------------------
>	Brad Sherman (bks@alfa.berkeley.edu)

David Duke.

david@cs.uq.oz.au