The Wolfram Functions Site

functions.wolfram.com contains the largest collection of identities for elementary and special functions ever assembled. The site is generated from a set of

*Mathematica* notebooks with typeset versions of all identities. The notebooks contain about 90,000 mathematical formulas. Because

*Mathematica* notebooks are structured ASCII files that can be processed and manipulated programmatically by the

*Mathematica* kernel,

*Mathematica* can read and "understand" the formulas. Therefore,

*Mathematica* can completely analyze and classify all the identities with respect to their mathematical structure and the functions that occur in them. The results of this analysis allow us to build a semantic search engine for mathematical identities. I will discuss the backend of the current mathematical search interface deployed on the Wolfram Functions site.