--<pre>
-- Generate a Fibonacci series

set(A,n,val)[i] = val when i=n, A[i]   dim[n]

f(n)=F[n] when known F[n],
     (F:={1}, 1) when n < 2,
     F:=set(F,n,f(n-1)+f(n-2)), F[n]

f(15):987
F:{1,2,3,5,8,13,21,34,55,89,...}