Hi Richard,
thanks for working on this topic. I think it is very important.
Part of the problem seems to be, that people fear that the distinction
between nouns and verbs is too complicated to explain to users. I
have argued against that in the past, perhaps
https://sourceforge.net/tracker/?func=detail&aid=902290&group_id=4933&atid=104933
(SF bug #902290) is the best example. - Unfortunatly I never got around
to write any code to try it.
I want to take the opportunity to point out that this didactical problem
could be mostly avoided by just distinguishing between nouns and verbs
very boldly - something like using uppercase for nouns and lower case
for verbs.
Why do you actually want to talk with a CAS about sin(0)=0?
I guess because the days when we tought new facts to CAS by writting
obscure code in some low level language are over. Nowadays we want
to type facts in the CASs own expression language - but other might
have different reasons...
Finally let me share a small experiment (it's nothing fancy, but the
point is: I consider myself a rather experienced user and in some cases
I had no idea what would be the output before actually trying):
(%i3) ?print(f);
$F
(%o3) f
(%i8) ?print(f(a,b));
(($F SIMP) $A $B)
(%o8) f(a,b)
(%i9) ?print("+"(a,b));
((MPLUS SIMP) $A $B)
(%o9) b+a
(%i11) ?print(nounify(f)(a,b));
((%F SIMP) $A $B)
(%o11) 'f(a,b)
(%i12) ?print(nounify("+")(a,b));
((%MPLUS SIMP) $A $B)
(%o12) '?mplus(a,b)
(%i13) ?print(nounify(""));
%
(%o13) \
(%i14) ?print(verbify(nounify("")));
$
(%o14) \
(%i15) ?print(verbify(nounify("+")));
MPLUS
(%o15) ?mplus
(%i16) ?print(verbify("+"));
MPLUS
(%o16) ?mplus
(%i17) ?print(sin(x));
((%SIN SIMP) $X)
(%o17) sin(x)
(%i18) ?print(verbify(sin)(x));
((%SIN SIMP) $X)
(%o18) sin(x)
(%i19) ?print(nounify(sin)(x));
((%SIN SIMP) $X)
(%o19) sin(x)
(%i20) ?print(sin);
%SIN
(%o20) sin
(%i21) ?print(verbify(sin));
$SIN
(%o21) sin
(%i22) ?print(nounify(sin));
%SIN
(%o22) sin
It's mostly consistent but still strange and it's often not clear
what's the point of the behaviour.
Harald
> A draft of a paper describing the situation is on
> http://www.cs.berkeley.edu/~fateman/papers/nounverbmac.pdf
>
> If you have suggestions on how to fill the (substantial) holes in it, I
> would be happy to include good stuff and insert
> your name as co-author.
> RJF
>
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