Number Theory/Notation and Introduction to proof

=Notation=

$$ \N \,$$ is the set of positive integers, also called the natural numbers.

$$ \Z \,$$ is the set of all integers.

$$ \mathbb{Q} \,$$ is the set of all rational numbers.

$$ \mathbb{A} \,$$ is the set of algebraic numbers.

$$ \R \,$$ is the set of real numbers.

$$ \Complex \,$$ is the set of complex numbers.

=Introduction to Mathematical Proof=