ERF EXTENDED _ _ _ _ _ _ _ _ _ _ _ _ operator

The special function package supplies an extended support for the erf operator which implements the error function

defint(e**(-x**2),x,0,infinity) * 2/sqrt(pi)

.

syntax:

examples:

erf(-x); 

  - erf(x)


on rounded; 

erf(0.35); 

  0.379382053562

The numeric values for the operator erf are computed via the power series representation, which limits the argument range.