fix ex3.30 ripple-carry-adder

Signed-off-by: Shulin <wangwangwar@gmail.com>
fixed adder test

Signed-off-by: Shulin <wangwangwar@gmail.com>
add main programs of constraint's propagation from p198 to p204

Signed-off-by: Shulin <wangwangwar@gmail.com>
add p205 ex3.33

Signed-off-by: Shulin <wangwangwar@gmail.com>
add p205 ex3.34 and ex3.35

Signed-off-by: Shulin <wangwangwar@gmail.com>
add p205 ex3.37

Signed-off-by: Shulin <wangwangwar@gmail.com>