The first thing you should do to analyze this is to create an ODE file which is a text file that XPPAUT use to solve differential equations. Here is the file
# hhh.ode par i=0 par ena=50 ek=-77 el=-54.4 gna=120 gk=36 gl=0.3 c=1 phi=1 am(v)=phi*.1*(v+40)/(1-exp(-(v+40)/10)) bm(v)=phi*4*exp(-(v+65)/18) ah(v)=phi*.07*exp(-(v+65)/20) bh(v)=phi*1/(1+exp(-(v+35)/10)) an(v)=phi*.01*(v+55)/(1-exp(-(v+55)/10)) bn(v)=phi*.125*exp(-(v+65)/80) v'=(I - gna*h*m^3*(v-ena)-gk*n^4*(v-ek)-gl*(v-el))/c m'=am(v)*(1-m)-bm(v)*m h'=ah(v)*(1-h)-bh(v)*h n'=an(v)*(1-n)-bn(v)*n init v=-65 m=.05 h=0.6 n=.317 doneThe file is typed in pretty much the same way you would if you were writing the equations; XPP is too stupid to recognize spaces for multiplication, so you have to put the ``*'' sign between quantities. Functions such as am(V) are defined in the obvious fashion. Parameters are declared with the par statement. They can be separated by spaces or commas. The ``='' sign, the parameter name, and its starting value must have NO spaces between them.
THIS IS WRONG:
par gl = .3
THIS IS RIGHT:
Initial data can be defined with the init statement. Each file must end with a done statement. Any line that starts with a # is a comment and ignored.