I want to get the zeroth order and first order perturbation equations of the following nonlinear coupled ODE.
restart; N := 1
alias(eta = e, theta = t)
eq[1] := 5*(diff(F(e), `$`(e, 3)))+(1+3/m)*F(e)*(diff(F(e), `$`(e, 2)))-(2+1/m)*(diff(F(e), e))^2-(4+2/m)*H(e)-(1-2/m)*e*(diff(H(e), e)) = 0
eq[2] := diff(H(e), e) = t(e)
eq[3] := 5*(diff(t(e), `$`(e, 2)))/Pr+(1+3/m)*F(e)*(diff(t(e), e))-5*(diff(F(e), e))*t(e)
eqs := eq[1], eq[2], eq[3]
F1 := unapply(add(F[i](e)/m^i, i = 0 .. N), e)
F2 := unapply(add(H[i](e)/m^i, i = 0 .. N), e)
F3 := unapply(add(t[i](e)/m^i, i = 0 .. N), e)
deqn := simplify(collect(subs({F(e) = F1(e), H(e) = F2(e), t(e) = F3(e)}, eqs), 1/m), {(1/m)^(N+1) = 0});
MAPLE says:
Error, (in simplify/siderels:-simplify/siderels) invalid side relations: Groebner basis contains the element 1ODE.mw
How do I correct it? There is no information available on the error in the internet.
Thanks.
