Lack of arguments for rules like `and` can make reconstruction hard

The rule and does not have as an argument the index of the conjunct that is concluded. This can be problematic because of the general ambiguity due to n-ary operators: (and a (and a b)) could be seen as both (and a a b) and (and a (and a b)).

I'd say then that the index could be given as an optional argument. What do you think?