a1=2
b1=3
a2=1.5
b2=1.8
f0(x,y0,y1)=(a1-b1*y1)*y0
f1(x,y0,y1)=(a2*y0-b2)*y1
m=MFehlberg([f0(x,y0,y1);f1(x,y0,y1)],[10,6],0,10,100)
PlotData(m[1][0],m[1][1])
