unlearn[op1, op2, ..., opn] sp
unlearn[*] sp
unlearn the given operator(s) for all the kets in sp
if * is used, then unlearn all supported operators, ie, everything
In some cases where an object has a lot of learn rules, it could be slow
The above is the constant operator version, here is the dynamic version:
unlearn(|op: foo-1> + |op: foo-2> + ...) list-of |kets>