Set notations

Standard Notations: x ∈ A x belongs to A or x is an element of set A. x ∉ A x does not belong to set A. ∅ Empty Set. U Universal Set. N The set of all natural numbers. I The set of all integers. I0 The set of all non- zero integers. I+ The set of all + ve integers. C, C0 The set of all complex, non-zero complex numbers respectively. Q, Q0, Q+ The sets of rational, non- zero rational, +ve rational numbers respectively. R, R0, R+ The set of real, non-zero real, +ve real number respectively.