Do you mean something like how you might define `append/3`

  append([], L, L).
  append([H|T], L2, [H|L3]) :- append(T, L2, L3).

Such that the computation can be run in any direction? Where it will produce the result of appending two lists, or the prefixes and suffixes of a list if the result (third parameter) is known, and so on?