// -0.5*[x(i+1)-x(i)] <= z <= 0.5*[x(i+1)-x(i)].
//
// Let Q(z)= (P(z)- S)/S, S = a0, rounded to 16 bits.
-// Polynomial coeffitients for Q(z) we have in the table erfc_Q_table as
+// Polynomial coefficients for Q(z) we have in the table erfc_Q_table as
// long double values
//
// We use multi precision to calculate input argument -x^2 for expl and