A more general form of Hill function.
Number: 4
Names: START, END, k, n
Meanings: START = Start, END = End, k = Michaelis constant, n = Cooperative sites
Lower Bounds: k>0, n>0
Upper Bounds: none
nlf_Hill1(x,START,END,k,n)
FITFUNC\HILL1.FDF
Growth/Sigmoidal