Akademik

restrict
verb
a) To restrain within bounds; to limit; to confine; as, to restrict worlds to a particular meaning; to restrict a patient to a certain diet.

If we restrict sine to , we can define its inverse.

b) To consider (a function) as defined on a subset of its original domain.
Syn: limit, bound, circumscribe, restrain, repress, curb, coerce

Wikipedia foundation.