2.3.3 - working

skip ex 2.58 for a while, since I don't have time today
start working on 2.58.b
ex 2.58 - done
ex 2.58 - correction
sets as unordered lists
ex 2.59 - done
ex 2.60 - impl
ex 2.60 - done
2.3.3 set as ordered list
ex 2.61 - done
ex 2.62 - done
sets as bin tree - start working
sets as bin - tree definition and element-of
2.3.3 sets as bin tree - done
ex 2.63 - working
ex 2.63 - example code
ex 2.63 - done
ex 2.64 - code and comments
ex 2.64 - explanation
ex 2.64 - result for converting (1 3 5 7 9 11)