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 minister is a politician who holds significant public office in a national or regional government, making and implementing decisions on policies in conjunction with the other ministers. Some ministers are more senior than others, and are usually members of the government's cabinet. In some countries the head of government is designated the  prime minister .