Boolean logic (named for the British-born Irish mathematician George Boole) is way to express relationships in logic arguments using the following three operators: "and", "or", "not".

The patent search systems use "AND", "OR", and "ANDNOT" as Boolean operators, in combination with parentheses to build nested logical subsets - example: needle ANDNOT ((record AND player) OR sewing), which would return anything with the word "needle" in a document as long as it does not also contain the word "record" and "player" in the same document or the word "sewing" in the same document. . It also uses some symbols such as "->" to indicate a range, where you enter the field code and start date, ->, and then the end date - example: ISD/1/1/1995->2/14/1995.

Source: U.S. Patent and Trademark Office.