As distinguished from a prison, it is a provincial institution for the punishment of lighter offences for which a prisoner has been sentenced to less than two years imprisonment. See the Prisons and Reformatories Act. Also applied to local police lock-ups or prisons where the prisoners are on remand awaiting their trial and have not been sentenced yet.
Gaol is a C++ library for interval arithmetic. It is designed to be fast and easy to use. It offers "relational" versions of common functions, which can be used to implement some algorithms for interval constraint solvers.