diff --git a/2021/day12.hs b/2021/day12.hs
index 0a721f7..875ab4f 100644
--- a/2021/day12.hs
+++ b/2021/day12.hs
@@ -1,18 +1,11 @@
 module Day12 where
--- import Data.HashSet (HashSet, member, insert, fromList)
--- import Data.Map ( Map, fromList, unionWith, empty, (!), insert, elems) qualified (map)
-import qualified Data.Map as M
 import Data.Bits ( Bits(shiftL, (.|.), (.&.)) )
+import Data.Char ( isUpper )
+import Data.List.Split (splitOn)
 
+import qualified Data.Map as M
 import qualified Data.Array as A
 
-import Data.HashSet (HashSet)
-import qualified Data.HashSet as S
-import Data.List.Split (splitOn)
-import qualified Data.Char
-
-import Debug.Trace ( trace )
-import GHC.Base (VecElem(Int16ElemRep))
 
 type Cave = Int
 type Path = (Cave,Cave)
@@ -25,8 +18,8 @@ readPath s = (from,to) where [from,to] = splitOn "-" s
 addPath :: (String,String) -> M.Map String [String] -> M.Map String [String]
 addPath (from,to) = M.unionWith (++) (M.fromList [(from,[to]), (to,[from])])
 
-isUpper :: Cave -> Bool
-isUpper x = x < 0
+isBig :: Cave -> Bool
+isBig x = x < 0
 
 solve :: System -> (Int, Int)
 solve sys = (pf1a A.! (1,1), pf2a A.! (1, 1))
@@ -40,8 +33,8 @@ solve sys = (pf1a A.! (1,1), pf2a A.! (1, 1))
         pf1 (-1) _ = 1
         pf1 x visited = sum $ map (\next -> pf1a A.! (next,nextmap next)) elig
             where
-                nextmap next = if not (isUpper next) then next .|. visited else visited
-                elig = filter (\cave -> isUpper cave || (cave .&. visited) == 0) (sys M.! x)
+                nextmap next = if not (isBig next) then next .|. visited else visited
+                elig = filter (\cave -> isBig cave || (cave .&. visited) == 0) (sys M.! x)
 
         pf2a :: A.Array (Cave,Int) Int
         pf2a = A.array bounds [((c,v), pf2 c v) | c <- [minimum caves..maximum caves], v <- [0..maximum caves * 2] ]
@@ -49,8 +42,8 @@ solve sys = (pf1a A.! (1,1), pf2a A.! (1, 1))
         pf2 (-1) _ = 1
         pf2 x visited = sum $ map (\next -> f next A.! (next,nextmap next)) elig
             where
-                nextmap next = if not (isUpper next) then next .|. visited else visited
-                f cave = if isUpper cave || (cave .&. visited) == 0 then pf2a else pf1a
+                nextmap next = if not (isBig next) then next .|. visited else visited
+                f cave = if isBig cave || (cave .&. visited) == 0 then pf2a else pf1a
                 elig = filter (/= 1) (sys M.! x)
 
 convert :: [String] -> M.Map String Int