On Wed, Feb 09, 2022 at 09:46:01PM +0100, Alexander Burger wrote:
> To take an example a bit simpler than the factorial function, you could start
> with addition as:
>
> (be + (@A @B @C)
> (^ @A (- @C @B)) )
> ...
Could not resist. I elaborated a little :)
If we define '+' as
# (+ 3 4 7)
# (+ 3 4 @X)
(be + (@A @B @C)
(^ @C (+ @A @B))
T )
# (+ 3 @X 7)
(be + (@A @B @C)
(^ @B (- @C @A))
T )
# (+ @X 4 7)
(be + (@A @B @C)
(^ @A (- @C @B))
T )
# (+ @X @Y 7)
(be + (@A 0 @A))
(be + (@A @B @C)
(^ @Z (dec @C))
(+ @A @Y @Z)
(^ @B (inc @Y)) )
then we can use it as
: (? (+ 3 4 7))
-> T
: (? (+ 3 4 @X))
@X=7
: (? (+ 3 @X 7))
@X=4
: (? (+ @X 4 7))
@X=3
: (? (+ @X @Y 7))
@X=7 @Y=0
@X=6 @Y=1
@X=5 @Y=2
@X=4 @Y=3
@X=3 @Y=4
@X=2 @Y=5
@X=1 @Y=6
@X=0 @Y=7
@X=-1 @Y=8
@X=-2 @Y=9
@X=-3 @Y=10
@X=-4 @Y=11
@X=-5 @Y=12
...
☺/ A!ex
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