Init: Solution to ex. 1-1
Init: Explores return value of a logical expression
Init: Explores the `cond` form
Init: Explores `cond` form further
Init: Explores whether `cond` form falls through
Init: Explores the `else` in the `cond` form
Init: Determines whether Scheme has a primitive `<=`
Init: Define operator
Init: Define an elegant `abs`