LASTN_CONV
listLib.LASTN_CONV : conv
Computes by inference the result of taking the last n elements of a list.
For any object language list of the form “[x0;...x(n-k);...;x(n-1)]” ,
the result of evaluating
LASTN_CONV “LASTN k [x0;...x(n-k);...;x(n-1)]”
is the theorem
|- LASTN k [x0;...;x(n-k);...;x(n-1)] = [x(n-k);...;x(n-1)]
Failure
LASTN_CONV tm fails if tm is not of the form described above, or k
is greater than the length of the list.