The boundary of a convex set is always a convex curve. The intersection of all convex sets containing a given subset A of Euclidean space is called the convex hull of A. It is the smallest convex set containing A.
Rector (ecclesiastical) A rector is, in an ecclesiastical sense, a cleric who functions as an administrative leader in some Christian denominations, and in Islam. In contrast, a vicar is also a cleric but functions as an assistant and representative of an administrative leader.
A dean, in a church context, is a cleric holding certain positions of authority within a religious hierarchy. The title is used mainly in the Anglican Communion, the Roman Catholic Church, and many Lutheran denominations. A dean's assistant is called a subdean.