ex 4.28 - done
ex 4.29 - first impl of memoization
ex 4.29 - memoization impl
ex 4.29 - explantions
ex 4.29 - correction
ex 4.29 - done
ex 4.30.a - done
ex 4.30.{b,c} - done
ex 4.30 - done
ex 4.31 - implement and test promise
ex 4.31 - `delay` impl
my-eval - test-all as a procedure
ex 4.31 - delay and force impl
ex 4.31 - some ideas about impl
ex 4.31 - (draft) stick to extension
ex 4.31 - define-eaa accessors
ex 4.31 - define-eaa - done
ex 4.31 - call-eaa - skeleton
ex 4.31 - done
Merge branch 'sicp'