This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Formal languages. en July diagram showing the syntactic divisions within formal system Strings of symbols may be broadly divided into nonsense and wellformed formulas The set of wellformed formulas is divided into theorems and nontheorems created this image myself on an image editor relinquish all rights to it Gregbard talk Uploads