ordsets:ord_selectchk/3

swipl
- library

ord_selectchk(+Item, ?Set1, ?Set2) is semidet

Selectchk/3, specialised for ordered sets. Is true when select(Item, Set1, Set2) and Set1, Set2 are both sorted lists without duplicates. This implementation is only expected to work for Item ground and either Set1 or Set2 ground. The "chk" suffix is meant to remind you of memberchk/2, which also expects its first argument to be ground. ord_selectchk(X, S, T) => ord_memberchk(X, S) & \+ ord_memberchk(X, T).

author: - Richard O'Keefe