\\ Kolmogorov-Smirnov test function, summing for t*k<=up.
\\ Checked vs. 1-Q(\lambda) in 2031 Fisz, 726.
t_ks (t,up=20,maxt=200) = {my (s,sgn,k,t2t2);
s=0; sgn=1; k=1; t2t2=2*t*t;
while ((k<=maxt)&&(t*k<=up),\
s+=(sgn*exp(-t2t2*k*k)); k+=1; sgn=-sgn); 2*s}