What is the font of this "p"?

Question

I'm typing a document using LaTeX. But the font of the "p" in the inequality $depth(M)\leq dim(A/p)$ (as in the following picture) is completely unknown to me.

Question: How do you type this "p" in latex?

Any help would be much appreciated!

Answer 1

According the comment of @DavidCarlisle, this is \wp.