Conference turris::languages

153.0. "MIRFAC - a strange language" by COMICS::DEMORGAN (Richard De Morgan, UK CSC/CS) Mon Nov 09 1987 11:30

Has anybody heard of the language MIRFAC?

It's probably obsolete now, but was in vogue in the late 50s/60s in
its original implementation (on an ICL 1900 series at the Admiralty
Underwater Weapons Establishment in England). Later on, sometime in
the early 70s, the software house I then worked for was attempting
to port it to the ICL 2900 series.

So what was so special about MIRFAC? First of all, I don't think is
was an acronym. The name was chosen because MIRFAC is the brightest
star in the same constellation as Algol. It was designed for
mathematicians - the notation being much the same. This posed problems
for program preparation - a special flexowriter (for those who are too
young to know what this is, it is like an ASR33, but with lower and
upper case and could intermix input from keyboard or tape so that
editing could be done on it. It was also about 50 times more reliable
than an ASR33) which had the ability to move the roller in both directions
and a special character set with Greek letters, backspace, and other
useful thinks. Thus a simple statement might be

                  2
            /oo -x
	y = |  e  .dx
            /o

but printed in a much more readable form (i.e. the integral sign and
infinity were special characters.)

The porting turned out to be difficult because nobody had bothered to
define the semantics properly, and 'bugs' that had become 'features'
had to be documented and faithfully reproduced. I never heard what happened
to it ...

This introduces the subject of two dimensional languages. Take for example

               r
	x := p + q
               s

where, I suppose + is a ????dic operator. It could be made even more
complicated by having different precedences in different directions.

I've read about some kind of 2D language in Jean Sammet's Tower of Babel
reference book.  I think it had a different name, though.  Could it have
been the Klerer-May system?

I think the actual star's name is Mirfak, unless the transliteration
rules for Arabic-to-English have changed recently.
				/AHM