# general replacement

I have 500 terms. and I want replace them with below function

rule1 := {
E^(Wr - (z___*Mr)/4 - (Gr*((Yr*Mr)/x___ + x___*Cr)) -
(Mr*((2*Mr)/y___ + (y___*Cr)/(2*Mr)))/2) :>

Ex[-(x+y+z)/4*Er^2]*
(-(Mr^2/x) - Mr^2/y - Cr/(x+y+z))
} ;


but I have some terms that don't have z (z=0) or y (y=0) for example:

E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - Gr (Cr x + (Mr Yr)/x) - (
Mr z)/4)


and rule1 couldn't contain all terms. how can I modify rule1 to contain all terms?

for example, I face this problem

term1 = E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - Gr (Cr x +
(Mr*Yr)/x) - (Mr z)/4)
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - Gr (Cr x + (Mr
Yr)/x))
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - (Mr z)/4)
+ E^(Wr - (1/2) Mr ((2 Mr)/y + (Cr y)/(2 Mr)));


after replacing only last term has changed

term1 //. rule1
E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)))
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - Gr (Cr x + (Mr Yr)/x))
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr))
- (Mr z)/4) + (-(Mr^2/x) - Mr^2/y - Cr/(x + y + z)) Ex[1/4 Er^2 (-x - y
- z)]

• You can not use the same name for 2 different things:" x___ + x_*Cr". Further in "(2*Mr)/y___ + (y___*Cr" y is the same expression, is this what you want? Nov 11, 2021 at 9:42
• dear @DanielHuber thanks for your comment I edited it but still, it doesn't work.
– asal
Nov 11, 2021 at 11:19
• rule1 now matches your expression: E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - Gr (Cr x + (Mr Yr)/x) - ( Mr z)/4) Nov 11, 2021 at 11:48
• dear@DanielHuber Again, the problem is not solved I think I did not explain my problem correctly, so I corrected the text, maybe my problem will be clearer
– asal
Nov 12, 2021 at 6:48

It is getting too complicated for a comment.

You may define the different cases as "Alternatives" like:

term1 = (E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) -
Gr (Cr x + (Mr*Yr)/x) - (Mr z)/4)
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) -
Gr (Cr x + (Mr Yr)/x))
+ E^(Wr - 1/2 Mr ((2 Mr)/y + (Cr y)/(2 Mr)) - (Mr z)/4)
+ E^(Wr - (1/2) Mr ((2 Mr)/y + (Cr y)/(2 Mr))));

rule1 := (E^(Wr - (Mr*((2*Mr)/y___ + (y___*Cr)/(2*Mr)))/2)) |
(E^(Wr - (Gr*((Yr*Mr)/x___ +
x___*Cr)) - (Mr*((2*Mr)/y___ + (y___*Cr)/(2*Mr)))/
2)) | (E^(Wr - (z___*Mr)/
4 - (Mr*((2*Mr)/y___ + (y___*Cr)/(2*Mr)))/
2)) | (E^(Wr - (z___*Mr)/
4 - (Gr*((Yr*Mr)/x___ +
x___*Cr)) - (Mr*((2*Mr)/y___ + (y___*Cr)/(2*Mr)))/2)) :>
Ex[-(x + y + z)/4*Er^2]*(-(Mr^2/x) - Mr^2/y - Cr/(x + y + z));


And then you get:

term1 /. rule1 • Dear @DanielHuber Thank you very much for your valuable comment. it solved my problem
– asal
Nov 13, 2021 at 8:09