Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 oracle(Arg1)

 oracle(Arg1, Arg2)

 oracle(Arg1, Arg2, Arg3)

 satisfiable(Arg1)

 ask_for(Arg1)

 ask_for_ex(Arg1)

 confirm(Arg1, Arg2)

 get_ci(Arg1, Arg2)