How to simplify ?



Hello,

I found that tex1 writes to string and then I can manipulate on string to get 
desired formatted string to put it into latex document and also I yesterday 
do misteke. I used infix instead of nary 
texput(".", "", nary)$ 
but now I have another problem. 

I work on matrices in control field and I define the following difference 
betwen error in r+1 and r iteration at position k

I have the following equation:
eq1:  e(r+1, k) - e(r, k) = C . x(r, k) - C . x(r+1, k)

Is there any possibility to tell maxima to simplify above eq1 to this form
e(r+1, k+1) - e(r, k+1) = C . ( x(r, k+1) - x(r+1, k+1) )

where:
e - is a vector of size [m,1]
x -is a vector of size  [n,1]
C - is a matrix of size [m,n]

Here I consider this equation in general (as a mathematical concept) so the 
matrix C and vector x and e do not have any values now. 

Thankyou in advance.

Zbigniew