Minutes June 3rd
Regarding the naming of subexpressions I'd like to point out two slightly
differing kinds of subexpression/expression naming relevant to producing
In AsTeR, you could name a cross-referencable object such as an equation with
meaningful names e.g. Fibonacci's formula instead of equation 1.13
--this made listening to cross-referenced material easier.
AsTeR also performed the other kind of sub-expression naming which I think got
discussed yesterday during the meeting.
I refered to this in AsTeR as "variable substitution".
--"folding" to use Dave's terminology--
AsTeR also implemented a fairly straight-forward naming algorithm for giving
meaningful names to sub-expressions e.g. "lower constraint 1" and denominator
The problem of recognizing that two subexpressions are identical is actually
very hard if you're working with a written/typeset document --AsTeR did not
attempt to do this. However, even without the intelligence to recognize two
semantically equivalent instances of a subexpression, "variable substitution"
or "folding" as Dave refers to it in his minutes is *really* useful for speech
and I suspect it would be very useful for small visual displays.
In fact after I implemented the variable substitution in AsTeR Rich Zippel at
Cornell pointed out that symbolic math systems in the early 70's had to
implement something analogous to display complex expressions since the
displays available at the time were not as graphically rich as what we have
Here are the relevant sections from the thesis:
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