Remove leftovers from EOPL

I attempted to start this book a few years ago. I want to start fresh
and use a structure much more alike my SICP exercises.
eopl; code for generating exercise stubs
eopl; exercise 1.01 - some recursive set definitions
eopl; exercise 1.02 - figure out some sets
eopl; exericse 1.03 - find a set T != S
eopl; exercise 1.04 - List-of-Int derivation
eopl; exercise 1.05 - proof by induction for LcExp
eopl; exercise 1.06 - reversing the tests in nth-element
eopl; exercise 1.07 - better error message for nth-element
eopl; exercise 1.08 - modify remove-first
eopl; exercise 1.09 - remove
eopl; exercise 1.10 - the other meaning of "or"
eopl; exercise 1.11 - why does subst halt?
eopl; exercise 1.12 - inline subst-in-s-exp
eopl; exercise 1.13 - rewrite w/ Kleene star
eopl; exercise 1.14 - "prove" partial-vector-sum
eopl; exercise 1.15 - duple
eopl; exercise 1.16 - invert
eopl; exercise 1.17 - down
eopl; exercise 1.18 - swapper