# What is the function of PhLi in this reaction?

Can someone please explain the mechanism of the reaction when we add 2 moles of $\ce{Ph3P}$ and $\ce{PhLi}$ to 1,2-dichloroethane.

I know this is a type of Wittig reaction but I am not able to figure out how the reaction will work out.

On adding $\ce{Ph_3P}$ to 1,2-dichloroethane , $\ce{PhLi}$ acts as an catalyst and eliminates $\ce{HCl}$ from both the carbons resulting in a phosphonium di ylide.