EX-1 Used let to reduce code duplication in do-a-thing
EX-2 Implemented function to sum v[0] and v[2] in a vector (spiff)
EX-3 Implemented cutify function to add <3 to the end of a vector
EX-4 Re-implemented spiff using destructuring
EX-5 Implemented rectangle height and width calculation using destructuring
EX-6 Implemented square?
EX-7 Implemented area function
EX-8 Implemented contains point function
EX-9 Implemented contains rectangle function
EX-10 Implemented title length function
EX-11 Implemented author count function
EX-12 Implemented multiple-authors? function
EX-13 Implemented add-author function
EX-14 Implemented alive? function
EX-15 Implemented collection element lengths function
EX-16 Implemented second elements function
EX-17 Implemented titles function
EX-18 Implemented stars method, using apply to inject the str funciton to the head of a sequence of args
EX-19 Implemented monotonic? method, note that this is not strictly monotonic as it allows duplication e.g. (1 2 2)
EX-20 Implemented toggle method