diff --git a/Simulation.hs b/Simulation.hs
new file mode 100644
--- /dev/null
+++ b/Simulation.hs
@@ -0,0 +1,66 @@
+module Simulation where
+
+import Data.Array
+
+data State = Alive | Dead deriving (Eq)
+type Row = Array Int State
+type Grid = Array Int Row
+
+data Board = Board {bGrid :: Grid, bRows :: Int, bCols :: Int} deriving (Show)
+data Coord = Coord Int Int deriving (Show)
+
+instance Num Coord where
+  Coord a b + Coord c d = Coord (a+c) (b+d)
+  Coord a b - Coord c d = Coord (a-c) (b-d)
+
+instance Show State where
+  show Alive = "■"
+  show Dead = " "
+
+directions :: [Coord]
+directions = [Coord y x | y <- [-1..1], x <- [-1..1], not (x==0 && y==0)]
+
+neighbors :: Board -> Coord -> [Coord]
+neighbors board coord = filter (\c -> state board c == Alive) validCoords
+  where
+  validCoords = filter (validCoord board) coordsAround
+  coordsAround = map (+ coord) directions
+
+validCoord :: Board -> Coord -> Bool
+validCoord board (Coord y x) = xValid && yValid
+  where 
+  xValid = x >= 0 && x < bCols board
+  yValid = y >= 0 && y < bRows board
+
+numNeighbors :: Board -> Coord -> Int
+numNeighbors board coord = length $ neighbors board coord
+
+state :: Board -> Coord -> State
+state board (Coord y x) = (bGrid board) ! y ! x
+
+singleStep :: Board -> Coord -> State
+singleStep board coord = stepCell currentState bors
+  where 
+  currentState = state board coord
+  bors = numNeighbors board coord
+
+stepCell :: State -> Int -> State
+stepCell Dead 3 = Alive
+stepCell Dead _ = Dead
+stepCell Alive n
+  | n < 2 = Dead
+  | n > 3 = Dead
+  | otherwise = Alive
+
+step :: Board -> Board
+step board = board {bGrid = newGrid}
+  where
+    newGrid :: Grid
+    newGrid = listArray (0, rs-1) $ map newRow [0..rs-1]
+
+    newRow :: Int -> Row
+    newRow y = listArray (0,cs-1) $
+                  [singleStep board (Coord y x) | x <- [0..(cs)-1]]
+
+    cs = bCols board
+    rs = bRows board 
diff --git a/game-of-life.cabal b/game-of-life.cabal
--- a/game-of-life.cabal
+++ b/game-of-life.cabal
@@ -2,7 +2,7 @@
 --  documentation, see http://haskell.org/cabal/users-guide/
 
 name:                game-of-life
-version:             0.1.0.2
+version:             0.1.0.3
 synopsis:            Conway's Game of Life
 -- description:         
 license:             MIT
@@ -18,7 +18,7 @@
 
 executable game-of-life
   main-is:             Main.hs
-  -- other-modules:       
+  other-modules:       Simulation
   -- other-extensions:    
   build-depends:       base >=4.7 && <4.8,
                        random,
@@ -27,4 +27,4 @@
                        text
   -- hs-source-dirs:      
   default-language:    Haskell2010
-  ghc-options:         -O2
+  -- ghc-options:         -O2