I have to translate a dissertation to a researcher. There is a problem I couldn't solve. Namely, there is an introduction chapter where the author has named an equation as `(A)`. Then in the chapter one there is again an equation named as `(A)`. Those equations are not the same in sense that first one has parameter `z` but another has parameter `e^z`. So how can I name two different equations with the same label? For example

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> `e^{ix}+1=0` (A)
> 
> 
> 

and

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> `$e^{iy}=-1$` (A)
> 
> 
>