gf kf kft kr krt lf - E^(-s t0) gf kf kft kr krt lf +

Dear All,

Here at the bottom you find the poly I'm working with. In the poly, I'd like to collect just for the term "s" but as you can notice, the term "s" is also present as exponent of e. If I do the command Collect[poly,s] , Mathematica is considering also this latter and the result I got is not what I want. Example: let'say I've got this poly: e^(-s)a + e^(-s)b+ c + s^5(d)+s^5(e)+s^5*(f) What I'd like to get is: s^5(d+e+f) + e^(-s)(a+b) + c. but actually what I got is: s^5(d+e+f) + e^(-s)(a+b+e^(s)*c). This result from an algebraic stand point is correct but is not what I want.. The reason is because "s" refers actually to the Laplace domain and in my application I need to use the equation by having the exponent "s" always negative. That's why I gotta dismiss the result I got from Mathematica. Anyone of you can help on this topic?

Regards,

gf kf kft kr krt lr - E^(-s t0) gf kf kft kr krt lr + 
cr gf kf kft krt lf s - cr E^(-s t0) gf kf kft krt lf s + 
cf gf kft kr krt lf s - cf E^(-s t0) gf kft kr krt lf s + 
cr gf kf kft krt lr s - cr E^(-s t0) gf kf kft krt lr s + 
cf gf kft kr krt lr s - cf E^(-s t0) gf kft kr krt lr s + 
cf cr gf kft krt lf s^2 - cf cr E^(-s t0) gf kft krt lf s^2 + 
cf cr gf kft krt lr s^2 - cf cr E^(-s t0) gf kft krt lr s^2 + 
gf kf kft kr lf m s^2 + gf kf kft krt lf m s^2 - 
E^(-s t0) gf kf kr krt lr m s^2 - E^(-s t0) gf kft kr krt lr m s^2 - 
E^(-s t0) gf kf kr krt lf mf s^2 - E^(-s t0) gf kf kr krt lr mf s^2 +
gf kf kft kr lf mr s^2 + gf kf kft kr lr mr s^2 + 
cr gf kf kft lf m s^3 + cf gf kft kr lf m s^3 + 
cf gf kft krt lf m s^3 - cr E^(-s t0) gf kf krt lr m s^3 - 
cr E^(-s t0) gf kft krt lr m s^3 - cf E^(-s t0) gf kr krt lr m s^3 - 
cr E^(-s t0) gf kf krt lf mf s^3 - cf E^(-s t0) gf kr krt lf mf s^3 -
cr E^(-s t0) gf kf krt lr mf s^3 - 
cf E^(-s t0) gf kr krt lr mf s^3 + cr gf kf kft lf mr s^3 + 
cf gf kft kr lf mr s^3 + cr gf kf kft lr mr s^3 + 
cf gf kft kr lr mr s^3 + cf cr gf kft lf m s^4 - 
cf cr E^(-s t0) gf krt lr m s^4 - cf cr E^(-s t0) gf krt lf mf s^4 - 
cf cr E^(-s t0) gf krt lr mf s^4 - E^(-s t0) gf kr krt lr m mf s^4 + 
cf cr gf kft lf mr s^4 + cf cr gf kft lr mr s^4 + 
gf kf kft lf m mr s^4 - cr E^(-s t0) gf krt lr m mf s^5 + 
cf gf kft lf m mr s^5