A Default Identity Value for Programming(michaelfeathers.silvrback.com)
michaelfeathers.silvrback.com
A Default Identity Value for Programming
https://michaelfeathers.silvrback.com/a-default-identity-value-for-programming
https://michaelfeathers.silvrback.com/a-default-identity-value-for-programming
J doesn't have user-defined types. In a language with user-defined types, you would probably have to declare which operations are monoids.