8c54d553_rch___Enoch_Pratt_Free_Library__Explanation
[Search Using:] Using +, -, OR ("Boolean") [Example] +idea -logical logical OR idea [Explanation] 
Finds each page based on the condition being met using "Boolean operators" (symbols for AND, OR, and NOT.) A plus (+) before a word indicates that the word MUST exist on the page. A minus (-) before a word indicates that the word MUST NOT exist on the page. An OR separator finds any page that contains either the word logical, or the word idea. The OR separator MUST be all uppercase.
Search - Enoch Pratt Free Library
Explanation