diff --git a/README.md b/README.md
index 33ba7b5..fb802d3 100644
--- a/README.md
+++ b/README.md
@@ -46,7 +46,7 @@ AST for the given input `il` file.
 
 ```bash
 $ nix-shell
-$ rtlil-parse test/corpus/xprop_dffe_1nnd_wrapped_xprop.il -o parsed1.ast
+$ rtlil-parse
 ```
 
 # TODO
diff --git a/src/RTLILParser/AST.hs b/src/RTLILParser/AST.hs
index e62784a..95ba77d 100644
--- a/src/RTLILParser/AST.hs
+++ b/src/RTLILParser/AST.hs
@@ -1,9 +1,9 @@
 module RTLILParser.AST(
-    AutoIdxStmt(..),    ParamStmt(..), AutogenId(..),
-    Constant(..),       CellStmt(..),  PublicId(..),
-    AttrStmt(..),       Value(..),     Id(..),
-    CellId(..),         CellType(..), WireId(..),
-    SigSpec(..)
+    AutoIdxStmt(..),    ParamStmt(..),  AutogenId(..),
+    Constant(..),       CellStmt(..),   PublicId(..),
+    AttrStmt(..),       Value(..),      Id(..),
+    CellId(..),         CellType(..),   WireId(..),
+    SigSpec(..),        Slice(..)
     ) where
 import Text.Read (Lexeme(Ident))
 import Data.Functor.Contravariant (Contravariant)
@@ -11,6 +11,7 @@ import GHC.RTS.Flags (DoCostCentres(CostCentresAll))
 
 data PublicId       = PublicId      String  deriving (Show)
 data AutogenId      = AutogenId     String  deriving (Show)
+data Slice          = Slice         Int (Maybe Int) deriving (Show)
 data Id             = Public    PublicId
                     | Autogen   AutogenId
                     deriving (Show)
@@ -23,7 +24,7 @@ data CellId         = CellId    Id deriving (Show)
 data CellType       = CellType  Id deriving (Show)
 data SigSpec        = SigSpecConstant   Constant
                     | SigSpecWireId     WireId
-                    | SigSpecSlice      SigSpec Int (Maybe Int)
+                    | SigSpecSlice      SigSpec Slice
                     | SigSpecConcat     [SigSpec]
                     deriving (Show)
 data Value = Value
diff --git a/src/RTLILParser/Parser.hs b/src/RTLILParser/Parser.hs
index bb46c11..faa5ee4 100644
--- a/src/RTLILParser/Parser.hs
+++ b/src/RTLILParser/Parser.hs
@@ -1,5 +1,5 @@
 -- this parser largely references:
--- https://github.com/YosysHQ/yosys/blob/111b747d2797238eadf541879848492a9d34909a/docs/source/yosys_internals/formats/rtlil_text.rst
+-- https://yosyshq.readthedocs.io/projects/yosys/en/stable/appendix/rtlil_text.html
 module RTLILParser.Parser(a, val) where
 
 
@@ -7,11 +7,11 @@ import Control.Monad (void)
 import Text.Parsec
 import Text.Parsec.String (Parser)
 import RTLILParser.AST(
-    AutoIdxStmt(..),    ParamStmt(..), AutogenId(..),
-    Constant(..),       CellStmt(..),  PublicId(..),
-    AttrStmt(..),       Value(..),     Id(..),
-    CellId(..),         CellType(..), WireId(..),
-    SigSpec(..)
+    AutoIdxStmt(..),    ParamStmt(..),  AutogenId(..),
+    Constant(..),       CellStmt(..),   PublicId(..),
+    AttrStmt(..),       Value(..),      Id(..),
+    CellId(..),         CellType(..),   WireId(..),
+    SigSpec(..),        Slice(..)
     )
 import Util(binaryStringToInt)
 import RTLILParser.Primitives(pEscapedChar)
@@ -20,6 +20,9 @@ import RTLILParser.Primitives(pEscapedChar)
 nonws :: Parser Char
 nonws = noneOf " \t\r\n"
 
+pMaybeWs :: Parser String
+pMaybeWs = many (oneOf " \t")
+
 pWs :: Parser String
 pWs = many1 (oneOf " \t")
 
@@ -105,12 +108,53 @@ pCellStmt = do
     _ <- pEol
     return $ CellStmt cellId cellType
 
+-- Parse a single slice
+pSlice :: Parser Slice
+pSlice =
+    Slice
+    <$> (char '[' *> pMaybeWs *> pInteger <* pMaybeWs)
+    <*> (optionMaybe (char ':' *> pInteger) <* pMaybeWs <* char ']')
 
--- pModuleStmt :: Parser ()
--- pModuleStmt = 
+pSigSpecConcat :: Parser SigSpec
+pSigSpecConcat = do
+    _           <- char '{' <* pWs
+    sigspecs    <- pSigSpec `sepBy` pWs
+    _           <- pWs <* char '}'
+    return $ SigSpecConcat sigspecs
+
+applySlices :: SigSpec -> Parser SigSpec
+applySlices base = do
+    maybeSlice <- optionMaybe pSlice
+    case maybeSlice of
+        Nothing -> return base
+        Just slice -> applySlices (SigSpecSlice base slice)
+
+pSingleSigSpec :: Parser SigSpec
+pSingleSigSpec = do
+    baseSigSpec <- (SigSpecConstant <$> pConstant) 
+                   <|>
+                   (SigSpecWireId   <$> pWireId)
+    applySlices baseSigSpec
+
+pSigSpec :: Parser SigSpec
+pSigSpec = 
+    try pSigSpecConcat -- Check for concatenation first
+    <|> pSingleSigSpec -- Otherwise parse a single sigspec
+
+
+-- would correspond to `123456789[0:9][0:8]`
+exampleSigSpecSlice = 
+    SigSpecSlice 
+        (
+            SigSpecSlice 
+            (SigSpecConstant (ConstantInteger 123456789)) 
+                (Slice 0 $ Just 9)
+        )
+            (Slice 0 $ Just 8)
 
 -- val = parse pInteger "pInteger" "721"
-val = parse pModuleStmt "pModuleStmt" "module \\top\n"
+-- val = parse pModuleStmt "pModuleStmt" "module \\top\n"
+val = parse pSigSpec "pSigSpecSlice" "123456789[0:9][0:8]"
 
 a :: Int
 a = 3
\ No newline at end of file