I am going through http://neuralnetworksanddeeplearning.com/chap1.html and not able to understand what the arrow notation represents in equation 11

I mean this equation

I am going through http://neuralnetworksanddeeplearning.com/chap1.html and not able to understand what the arrow notation represents in equation 11

I mean this equation

Reading through the article it seems the arrow means when v is changed to v’. Is that correct?