Symbol	Meaning
$\mathbb{N}$	The set of natural numbers
$\mathbb{R}$	The set of reals
${\mathbb{R}}_{+}$	The set of non-negative reals
1{A}(x)	Indicator (characteristic) function of the set A
δx	Dirac delta function at x
$\mathcal{B}(A)$	The Borel σ-field of subsets of a set A
${\mathcal{M}}_P(E)$	The space of finite point measures on the set E
D([0, T], E)	The space of E-valued càdlàg functions defined on [0, T]
⟨μ, f⟩	The integral ʃ f dμ