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.
Characters[edit] Anna Frith, the protagonist of the novel, is employed as a young housemaid at the Rector's house. Widowed with two young sons at age 18, she witnesses first-hand the trauma of the plague, as her house-guest, children and neighbours all sicken and die.