Wolfram LibraryLink allows dynamic libraries to be directly loaded into the Mathematica kernel so that functions in the libraries can be immediately called from Mathematica. ...
ArcCot
(Built-in Mathematica Symbol) ArcCot[z] gives the arc cotangent cot -1 (z) of the complex number z.
KelvinBei[z] gives the Kelvin function bei(z).KelvinBei[n, z] gives the Kelvin function bei_n (z).
KelvinBer[z] gives the Kelvin function ber(z).KelvinBer[n, z] gives the Kelvin function ber_n (z).
KroneckerDelta[n_1, n_2, ...] gives the Kronecker delta \[Delta] Subscript[n, 1] Subscript[n, 2] ..., equal to 1 if all the n_i are equal, and 0 otherwise.
GCD
(Built-in Mathematica Symbol) GCD[n_1, n_2, ...] gives the greatest common divisor of the n_i.
ScalarTripleProduct[v_1, v_2, v_3] gives the scalar triple product of the three 3-vectors v_1, v_2 and v_3 in the default coordinate system. ScalarTripleProduct[v_1, v_2, ...
BesselK
(Built-in Mathematica Symbol) BesselK[n, z] gives the modified Bessel function of the second kind K_n (z).
KelvinKei[z] gives the Kelvin function kei(z).KelvinKei[n, z] gives the Kelvin function kei_n (z).
KelvinKer[z] gives the Kelvin function ker(z).KelvinKer[n, z] gives the Kelvin function ker_n (z).