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.
Finally, a president of a Catholic university is rector over the university and, if a priest, often the rector of any church that the university may operate, on the basis that it is not a canonical establishment of a parish (c. 557 Â§3).