$erfc\left(x\right)$	complementary error function, Equation (50)
$H_k\left(x\right)$	Hermite polynomials, $k=0,1,2,\dots$, Equations (45) and (46)
$L_k\left(x\right)$	Laguerre polynomials, $k=0,1,2,\dots$, Equation (33)
$P_k\left(x\right)$	Legendre polynomials, $k=0,1,2,\dots$, Equations (A1)–(A3)
$T_k\left(x\right)$	Chebyshev polynomials of the first kind, $k=0,1,2,\dots$, Equations (36) and (37)
$L^2\left(0,\right.\left.\mathrm{\infty }\right)$	space of real-valued square-integrable functions on the interval $\left(0,\right.\left.\mathrm{\infty }\right)$
$\mathcal{L}\left[f\left(v\right)\right]$	Laplace transform of the function $f\left(v\right)$
$\Gamma \left(n\right)$	Euler’s gamma function
${‖·‖}_2$	square norm in the real Euclidean space ${\mathcal{R}}^N$ and in $L^2\left(0,\right.\left.\mathrm{\infty }\right)$
$\underset{x}{min}f\left(x\right)$	find the value of $x$, which minimizes the function $f\left(x\right)$