The Results Returned

Renze also implemented the format of the results. All the formulas found are, by default, presented as gifs and have hyperlinks to the corresponding page of the Wolfram Functions site. The identities can be downloaded in StandardForm in notebooks or in TraditionalForm in pdf files.

Google, the de facto standard for searching today, has a Similar pages search button. Everyone would agree that and are similar identities. This suggests that a working definition of "similar" would include all identities that contain other functions from the same group in semantically equivalent positions. We implemented a search for similar identities using a Hamming-type distance function. It treats functions from the same group as equivalent and adds a few rules to make operations such as differentiation and integration similar. To my surprise, the resulting search worked unexpectedly well. So, we continued refining the definition for "similar," and the current functionality seems useful and natural.