first commit - starting SICP :)
1.1.2 - done
1.1.3 - done
1.1.5 - done
exercise 1.1 - done
exercise 1.{2,3} - done
exercise 1.{4,5} - done
exercise 1.5 - some correction
1.1.7 - done
final correction on exercise 1.5
exercise 1.6 - done
exercise 1.7 - working
working on exercise 1.7 - skeleton
exercise 1.7 - done
exercise 1.8 - done
1.1.8 - done
1.2.1 - done
exercise 1.9 - done
exercise 1.10 - working
exercise 1.10 - need verification