Good morning to all,
I wanted to post this question here hoping to have more details. The concern, in my opinion, comes from the fact that the concept of "closed-form" is not clear. Because, on the one hand, we have the algebraists who say that the gaussian function (error function) cannot have an analytical expression and, on the other hand, we have the financiers who accept that any formula for the price of a product is considered a closed-form if it is written with the gaussian function (as in the case of the Black-Scholes formula) or any other function whose values are known in the tables.
My question is thus the following one: In option pricing theory, what exactly does a closed-form formula mean ?