AAFPA/Ch4 - 大久保弘崇

p.75 L.-9

"reverse' [] y" is redundant.

p.79 definition of count_depth

"depth" should be "depth'"

p.81 definition of tinsert

function "size" is trivial, but not given.

Section 4.2.6 Comment

Type "BinTreeSz" has valid value (Pair of Int has the size of subtrees) and invalid value.
It is the programmer's task to keep validity of BinTreeSz value while manipulating them.
This kind of datatype breaks the reliability which Haskell's type system provides.