hi @Christopher2222 

i didnt understand ur mean, how can i use `` ??

there is an error, any sol.??

restart;  A:=(``-cos(theta)+1)*z^2+cos(theta)  local cos:   B:=op([1,2], A)*(1-cos(theta))+op(2, A):  B;
Error, unable to parse

hi @Kitonum

i tried this code but the output is the same, only z^2 is ordered.

i dont know why!!

restart; A := (-cos(theta)+1)*z^2+cos(theta); _local(cos); B := op([1, 2], A)*(-cos(theta)+1)+op(2, A); B;
Warning, A new binding for the name `cos` has been created. The global instance of this name is still accessible using the :- prefix, :-`cos`.  See ?protect for details.
                2                               
               z  (-cos(theta) + 1) + cos(theta)
 

thank u @acer I solved the problem.

@Kitonum  can u convert ss_new.mw to maple 18 plz,  its newer verion

@acer 

thank u for reply

but i delet the extra spaces, still the same problem !

also i used the simplify in previous eq (5) as u can see  ss.mw and it worked correctly.

the .mw file is attached here , ss.mw could u help m plz???