Solved ex1.1 and ex1.2
Solved 1.3, 1.4
Solved 1.5
Merge pull request #2 from naoiwata/master

Solved ex1.1 to ex1.5
An infinite recursive call is not an infinite loop
Merge pull request #4 from cocoatomo/master

An infinite recursive call is not an infinite loop
sicp chapter1 exercise1.9~1.10