Thanks @Kitonum for your positive and quick response!

@acer @Carl Love @Kitonum @Preben Alsholm

@tomleslie thanks for your kind response!

@Carl Love thanks for your kind response!

@mmcdara 

thank you so much for your help.

@acer @Carl Love @Kitonum

@Kitonum dear I want to compare the coefficient of like powers of exponential function of the following attached file. When I run the program I got the following error

Error, invalid input: coeff received 1, which is not valid for its 2nd argument, x
Help.mw

@acer @Carl Love @Kitonum

@Carl Love @tomleslie thanks for your valuable comments

@vv how we replace exp(eta*k2) with Z^k2?

@vv Thanks your vaulable comments. Now, I want to construct system of equations by comparing the likes powers of x^i*y^j*t^k1*exp(k2*eta) for an expression H1 present in attached file. Please see the fix my problem. I shall be very thankful for your kind help.

Help.mw

@acer @Carl Love @Kitonum @Preben Alsholm

@tomleslie I am going to compare the coefficiets and used the following command

printlevel := 2; Equation := 4;
for i from 0 by 1 while i <= Equation do 
for j from 0 by 1 while j <= Equation do 
C[i, j] := eval(g(i, j)) 
end do end do

but got the following errer.

g called with arguments: 0, 0
 #(g,1): coeff(collect(algsubs(x^n*y^m = z,select(j -> patmatch(j,a::anything*x^n*y^m),H1)),z),z)
Error, (in algsubs) no variables appearing rationally in pattern
 locals defined as: g = g, pat = 1, rep = z, vars = [], opt = remainder, v = v, bad = bad
Please see the attachement

coeffs.mw

@tomleslie dear thanks for your valuable comments!

@acer @Carl Love @Kitonum @Preben Alsholm