# XPP will disregard lines starting with #
u'=u*(1-u-a*v)
v'=v*(1-b*u-v)
# list the parameters
par a=1.2,b=.8
# the rest is not required, can be adjusted within XPP
# axis boundaries
@ xlo=0,ylo=0,xhi=1.2,yhi=1.2
# axis variables
@ xp=u,yp=v
done