# the henon map
x'=1-a*x^2+y
y'=b*x
a'=a
aux w=x^2+y^2
par b=.1
init x=.1,y=.1,a=0.25
@ xp=a,yp=y,xlo=0.25,xhi=2,ylo=-.4,yhi=.4
@ maxstor=100000,total=800,trans=350,meth=discrete
done