Algebraic Geometry, Definition of a field

A set of elements (e.g., a, b, and c) with two laws of composition, addition and multiplication, that obey the rules A, B, and C is called a field. Other examples of fields are the rational numbers (integers as well as all numbers obtainable as ratios of integers that are not zero, together with field properties, constituting the field Q), and the integers modulo a prime number p (the integers