[TUHS] Lorinda Cherry

Andrew Hume andrew at humeweb.com
Wed Feb 16 10:35:09 AEST 2022

for many years, my office was diagonally opposite lorinda’s.
we worked together most closely on the Unix manuals
(ninth and tenth editions); lorinda spent considerable work
on the permuted indices and the papers on Volume 2.

she also shared in my my own weird story of synchronicity.
i had been doing some work on polyhedra composed of
regular polyhedra. to prove to myself that i had gotten things
correct, i constructed a folding program to form the polyhedra
by folding a flat network of faces. i did this in bc and verified that
the vertices were sufficiently close together. and indeed, as i increased
the precision, the points coincided. except one didn’t.
for one polyhedra, one vertex stubbornly never got closer
than about 1e-6 from its (supposedly) coincident alter points.
it took about 3-4 days before i found the problem; in some exceptionally
rare cases, division in bc yielded the wrong answer.
i race around to lorinda to show her the problem (it was in the underlying
dc code). to my astonishment, lorinda listened and said
“you know, not 30 minutes ago, Vic Vyssotsky (our executive director)
came in with exactly the same problem.” he had discovered it by using
an extremely long-winded cyclical calculation used to detect errors
in arithmetic units. she then discovered the bug occurred when she converted
the original assembler code into C. the weird part was that this bug
had been latent for some years, and two different people reported it
to her with 30 minutes.

More information about the TUHS mailing list