Actually have a test in Exercise 1.02.
Simplify and idiomise conditionals.
Favour Clojure's maths library over java.lang.Math.
Use one implementation of `approximately?` everywhere.
Formatting.
Realised the `all-equal?` function is useless.
More formatting.
Simplified the logic in Exercise 1.29 a bit.
Implemented `double` in Exercise 1.41 without `comp`. That's the next exercise.
Lambdas are great. Use them.
`expt` is well known. We can import it.
Favour `inc` and `dec` instead of `(+ x 1)` and `(- x 1)`.
Massively simplified the `average` function in Exercise 2.2.
Exercise 2.3.
Simplified the `Segment` record in Exercise 2.2.
Ignored the book for Exercise 2.3 and stopped using coordinates.
Use `reify` to avoid making calculations more than once.
Exercise 2.4.
Exericse 2.5.
Exploratory testing of Church numerals for Exercise 2.6.