--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agda/basic.agda	Tue Oct 07 14:55:40 2014 +0900
@@ -0,0 +1,10 @@
+module basic where
+
+id : {A : Set} -> A -> A
+id x = x
+
+_∙_ : {A B C : Set} -> (A -> B) -> (B -> C) -> (A -> C)
+f ∙ g = \x -> g (f x)
+
+postulate String : Set
+postulate show   : {A : Set} -> A -> String
\ No newline at end of file

--- a/agda/similar.agda	Tue Oct 07 14:53:56 2014 +0900
+++ b/agda/similar.agda	Tue Oct 07 14:55:40 2014 +0900
@@ -1,23 +1,16 @@
 open import list
+open import basic
 open import Relation.Binary.PropositionalEquality
 open ≡-Reasoning
 
 module similar where
 
-id : {A : Set} -> A -> A
-id x = x
-
-postulate String : Set
-postulate show   : {A : Set} -> A -> String
-
 data Similar (A : Set) : Set where
   similar : List String -> A -> List String -> A -> Similar A
 
-
 fmap : {A B : Set} -> (A -> B) -> (Similar A) -> (Similar B)
 fmap f (similar xs x ys y) = similar xs (f x) ys (f y)
 
-
 mu : {A : Set} -> Similar (Similar A) -> Similar A
 mu (similar lx (similar llx x _ _) ly (similar _ _ lly y)) = similar (lx ++ llx) x (ly ++ lly) y
 
@@ -31,9 +24,6 @@
 returnSS x y = similar [[ (show x) ]] x [[ (show y) ]] y
 
 
-_∙_ : {A B C : Set} -> (A -> B) -> (B -> C) -> (A -> C)
-f ∙ g = \x -> g (f x)
-
 monad-law-1 : mu ∙ (fmap mu) ≡ mu ∙ mu
 monad-law-1 = {!!}