## Using Limit with the Option Assumptions

I want to calculate the following limit

 L=\lim_{r \to 0} \left( 1 + r \frac{El^{‘}(r)}{El(r)} \right)

by letting Mathematica to know

 \lim_{r \to 0} \frac{El^{‘}(r)}{El(r)} = A 

where $A$ is a constant. It is evident that we should have $L=1$ .

I used the following

Limit[1 + (r Derivative[1][El][r])/El[r], r -> 0,
Assumptions -> {Limit[Derivative[1][El][r]/El[r], r -> 0] == a}]



But it didn’t work.

What should I do?

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