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Chapter 3 Mathematical Notations

This is a table of mathematical notation used in university courses which may be unfamiliar to some students.
Table 3.0.1.
\(\forall\) For all
\(\exists\) There exists
\(\implies\) Implies
\(\therefore\) Therefore
\(a \neq b\) \(a\) is not equal to \(b\)
\(\emptyset\) The empty set
\(\{a,b,c\}\) An explicit set with these three elements
\(a \in A\) \(a\) is an element of the set \(A\)
\(A \subset B\) \(A\) is a subset of the set \(B\)
\(\{ a \in A \big| a \text{ is something }\}\) All \(a \in A\) that satisfy a property
\(A \cup B\) The union of the sets \(A\) and \(B\)
\(A \cap B\) The intersection of the sets \(A\) and \(B\)
\(A \setminus B\) The elements of the set \(A\) which are also not in the set \(B\)
\(\NN\) The natural numbers: \(\{1,2,3, \ldots \}\)
\(\ZZ\) The intergers: \(\{\ldots, -2,1,0,-1,2, \ldots \}\)
\(\QQ\) The rational numbers
\(\RR\) The real numbers
\(\CC\) The complex numbers
\(f: A \rightarrow B\) A function from \(A\) to \(B\)
\(f(x) \Big|_{x=a}\) The evaluation of a function at a point
\(f \circ g\) The composition of the functions \(f\) and \(g\)
\((a,b)\) The open interval \(a \lt x \lt b \subset \RR\)
\([a,b]\) The closed interval \(a \leq x \leq b \subset \RR\)
\((a,b]\) The half-open interval \(a \lt x \leq b \subset \RR\)
\([a,b)\) The half-open interval \(a \leq x \lt b \subset \RR\)