A letter of the alphabet drawn with doubled vertical strokes is called doublestruck, or sometimes blackboard bold (because doublestruck characters provide a means of indicating bold font weight when writing on a blackboard).
Usage. The capital Latin letter Z is used in mathematics to represent the set of integers. Usually, the letter is presented with a "double-struck" typeface to indicate that it is the set of integers.
The set of all rational numbers, also referred to as "the rationals", the field of rationals or the field of rational numbers is usually denoted by a boldface Q (or blackboard bold.
is an element ofThe symbol ∈ indicates set membership and means “is an element of” so that the statement x∈A means that x is an element of the set A. In other words, x is one of the objects in the collection of (possibly many) objects in the set A.
Z is the set of integers, ie. positive, negative or zero. Z∗ (Z asterisk) is the set of integers except 0 (zero). The set Z is included in sets D, Q, R and C.
Special sets Z denotes the set of integers; i.e. {…,−2,−1,0,1,2,…}. Q denotes the set of rational numbers (the set of all possible fractions, including the integers). R denotes the set of real numbers.
\mathbb N makes the slanted line bold.Apr 17, 2019
DESCRIPTION. \mathbb command is used to turn on blackboard-bold for uppercase letters and lowercase 'k'. If lowercase blackboard-bold letters are not available, then they are typeset in a roman font.
To write text in bold font, use a double asterix or underscores before and after the text.Oct 24, 2016
A and B in algebra stand for any variables of real numbers.
The union of a set A with a B is the set of elements that are in either set A or B. The union is denoted as A∪B.
1 : the science of numbers and their operations (see operation sense 5), interrelations, combinations, generalizations, and abstractions and of space (see space entry 1 sense 7) configurations and their structure, measurement, transformations, and generalizations Algebra, arithmetic, calculus, geometry, and ...