In Section 3.2.3, removed needless Englisth text
In Figure 3.12, "and" must be "と"
special form: 特別(な)形式 → 特殊形式
Excercise 3.52: Removed unnecessary English text
lambda calculus: Enzan -> Keisan
Add contributors in Chapter Unofficial Japanese Translation
Applyed patches from Kimura-san (Thanks\!) and some little fixes (See tex file history for details.)