"Strong typing vs. strong testing"

[Thomas A. Russ]

Malcolm McLean <malcolm.mclean5 at btinternet.com> writes:

> I'd like to design a language like this. If you add a quantity in
> inches to a quantity in centimetres you get a quantity in (say)
> metres. If you multiply them together you get an area, if you divide
> them you get a dimeionless scalar. If you divide a quantity in metres
> by a quantity in seconds you get a velocity, if you try to subtract
> them you get an error.

Done in 1992.

See 
 <http://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/lang/lisp/code/syntax/measures/0.html>
 citation at <http://portal.acm.org/citation.cfm?id=150168>

and my extension to it as part of the Loom system:
   <http://www.isi.edu/isd/LOOM/documentation/loom4.0-release-notes.html#Units>

-- 
Thomas A. Russ,  USC/Information Sciences Institute