delim $$ NAME erf, erfc - error function SYNOPSIS #include <math.h> double erf(x) double x; double erfc(x) double x; DESCRIPTION These functions calculate the error function erf(x) = (2/sqrt(pi)) integral from 0 to x exp(t^2) dt and the com- plementary error function erfc(x) = 1 - erf(x). The error criterion for both erf and erfc is relative. DIAGNOSTICS There are no error returns. delim off