diff --git a/aop-prelude.cabal b/aop-prelude.cabal
--- a/aop-prelude.cabal
+++ b/aop-prelude.cabal
@@ -4,7 +4,7 @@
 -- http://haskell.org/cabal/users-guide/
 
 name:                aop-prelude
-version:             0.4.1.1
+version:             0.4.1.2
 synopsis:            prelude for Algebra of Programming
 description:         prelude for Algenra of Programming, the original code was created by Richard Bird.
 homepage:            https://github.com/cutsea110/aop-prelude.git
@@ -21,7 +21,7 @@
   exposed-modules:     AOPPrelude
   -- other-modules:
   other-extensions:    NoImplicitPrelude
-  build-depends:       base >=4.12.0.0 && <4.16, ghc-prim >=0.5.3 && <0.8, integer-gmp
+  build-depends:       base >=4.12.0.0 && <4.19, ghc-prim >=0.5.3, integer-gmp
   hs-source-dirs:      src
   default-language:    Haskell2010
 
@@ -30,4 +30,4 @@
   type:                exitcode-stdio-1.0
   hs-source-dirs:      test
   main-is:             MyLibTest.hs
-  build-depends:       base >=4.12.0.0 && <4.16, ghc-prim >=0.5.3 && <0.8, aop-prelude
+  build-depends:       base >=4.12.0.0, ghc-prim >=0.5.3, aop-prelude
diff --git a/src/AOPPrelude.hs b/src/AOPPrelude.hs
--- a/src/AOPPrelude.hs
+++ b/src/AOPPrelude.hs
@@ -223,7 +223,7 @@
 
 inits :: [a] -> [[a]]
 inits = catalist ([[]], extend)
-  where extend (a, xs) = [[]] ++ list (a:) xs
+  where extend (a, xs) = [] : list (a:) xs
 tails :: [a] -> [[a]]
 tails = catalist ([[]], extend)
   where extend (a, x:xs) = (a:x):x:xs
@@ -300,13 +300,13 @@
 -- Word and line processing functions: ------------------------------
 words :: String -> [String]
 words = filter (not . null) . catalist ([[]], cond ok (glue, new))
-  where ok (a, xs)     = (a /= ' ' && a /= '\n')
+  where ok (a, xs)     = a /= ' ' && a /= '\n'
         glue (a, x:xs) = (a:x):xs
         new (a, xs)    = []:xs
 
 lines :: String -> [String]
 lines = catalist ([[]], cond ok (glue, new))
-  where ok (a, xs)     = (a /= '\n')
+  where ok (a, xs)     = a /= '\n'
         glue (a, x:xs) = (a:x):xs
         new (a,xs)     = []:xs