2/2021 - 8/2022 (update to version 2.6.0)
Authors: Raef Khan, Kaustubh Ghosal, and Pinhan Zhao
Implemented Associativity and Commutativity.
Added bracket highlighting. Brackets now highlight green if there is a matching bracket, and red if a bracket is missing.
The calculator will now throw an error if a word is defined multiple times in the exercise file.