Symbols, and relationships in mathematics

$=$	Equal
$\ne$	Not equal
$\approx$	Approximately equal
$>, ⩾$	Bigger, bigger, or equal. For example $a>b$ : a is bigger than b
$<,\le$	Smaller, smaller, or equal
$\in , \notin$	Element of, not element of set
$\subseteq , \subset$	Subset, proper subset
$\cup , \cap$	Union of sets, intersection of sets
	Relative complement
$\odot , △$	Symmetric difference of sets
$\times$	Cartesian producta, vectorial product
$\neg$	Logical negation
$\vee , \wedge$	Logical disjunction (or), logical conjunction (and)
$\iff , \oplus$	Logical equivalence, exclusive or (XOR)
$\Rightarrow$	Logical implication
$\forall$	For all
$\exists$	There exist
$\left|a\right|$	AAbsolute value of number a
$\sum _{}$	Summation
$\prod _{}$	Product of sequences
$!$	Factorial
${\int }_{}$	Indefinite Integrals
${\int }_a^b$	Definite Integrals
$\sphericalangle$	Angle
$R ⦜⦝$	Right angle
$\perp$	Perpendicular
$\parallel$	Parallel
$~$	Similar
$\cong$	Coincident
mod	Remainder after division
lim	Limit, limes
exp	Exponential function
log, lg, ln	Logarithm
$\varnothing$	Empty set
$\mathrm{\mathbb{N}}$	Natural Numbers
$\mathrm{\mathbb{Z}}$	Integers
$\mathrm{\mathbb{Q}}$	Rational Numbers
$\mathrm{ℝ}$	Real numbers
$\mathrm{ℂ}$	Complex numbers
$\infty$	Infinity