erf(x)

Error Function,  

ndl(x)

Normal law of probability distribution 

J(n,x)

J_n(x), Bessel function  of the 1st kind, n-th order

Y(n,x)

Y_n(x) , Bessel function  of the 2nd kind, n-th order

T(n,x)

T_n(x) , Chebyshev polynomial of n-th order

P(n,x)

P_n(x) , Legendre polynomial of n-th order