# tri
x'=2*z/(1+a*x+(1-a)*z)
y'=x
z'=y
par a=0.5
init x=1.1,y=1.2,z=1
@ xp=x,yp=y,xlo=-1,xhi=3,ylo=-1,yhi=3
@ total=200,meth=discrete,maxstor=40000
done