In mathematics, especially in set theory, a setA is a subset of a set B, or equivalently B is a superset of A, if A is "contained" inside B, that is, all elements of A are also elements of B. A and B may coincide. The relationship of one set being a subset of another is called inclusion or sometimes containment.
A diacritic – also diacritical mark, diacritical point, diacritical sign from ancient Greek διά ( dia, through) and κρίνω ( krinein, to separate) – is a glyph added to a letter, or basic glyph. The term derives from the Greek διακριτικός ( diakritikós, "distinguishing"). Diacritic is primarily an adjective, though sometimes used as a noun, whereas diacritical is only ever an adjective. Some diacritical marks, such as the acute ( ´ ) and grave ( `&thins..
