dx/dt=k1-(k2p+k2pp*y)*x
dy/dt=-k4*m*x*y/(j4+y)+(k3p+k3pp*a)*(1-y)/(j3+1-y)
da/dt=k5p+k5pp*(m*x)^n/(j5^n+(m*x)^n)-k6*a
dm/dt=mu*m*(1-m/mstar)
par k1=.04,k2p=.04,k2pp=1
par k3p=1,k3pp=10,k4=35,j3=.04,j4=.04
par k6=.1,k5pp=.2,k5p=.005,j5=.3,n=4
par mu=.01,mstar=10
par xthr=0.1
global -1 x-xthr {m=.5*m}
init x=.1,y=.9,a=.2,m=.6
@ total=150,dt=.05,meth=qualrk,tol=1e-6,atol=1e-6
@ nplot=4,xhi=150,yp=x,yp2=y,yp3=a,yp4=m
@ xp2=t,xp3=t,xp4=t,ylo=0,yhi=1.5
done