diff --git a/lvtc/app/Args.hs b/lvtc/app/Args.hs
index 5d40246..56ae89a 100644
--- a/lvtc/app/Args.hs
+++ b/lvtc/app/Args.hs
@@ -22,7 +22,8 @@ data Args = Args {
     action :: Action,
     folderPath :: String,
     outFile :: String,
-    verbose :: Bool
+    verbose :: Bool,
+    folders :: [String]
 }
 
 parseArgs' :: [String] -> Args -> Either Args String
@@ -42,6 +43,10 @@ parseArgs' ["-o"] _ =
     Right "Missing argument for -o"
 parseArgs' ("--verbose":xs) args =
     parseArgs' xs (args {verbose = True})
+parseArgs' ("--lib":x:xs) args =
+    parseArgs' xs (args {folders = x : folders args})
+parseArgs' ("-l":x:xs) args =
+    parseArgs' xs (args {folders = x : folders args})
 parseArgs' (('-':xs):_) _ =
     Right ("Unknown option: " ++ xs)
 parseArgs' (x:xs) args =
@@ -51,7 +56,8 @@ parseArgs :: [String] -> IO (Either Args String)
 parseArgs args =
     getCurrentDirectory >>= \path ->
     return (parseArgs' args (Args {
-        action = Run, folderPath = path, outFile = "out.wasm", verbose = False
+        action = Run, folderPath = path, outFile = "out.wasm",
+        verbose = False, folders = []
     }))
 
 hLine1 :: String
@@ -77,9 +83,11 @@ hLine9 = part1 ++ part2
         part2 = " source code recursively from FOLDER\n"
 hLine10 :: String
 hLine10 = "\t--verbose\n\t\tVerbose mode\n"
+hLine11 :: String
+hLine11 = "\t-l, --lib\n\t\tAdd folder to compiled Leviator source code\n"
 
 printHelp :: IO ()
 printHelp =
     putStr hLine1 >> putStr hLine2 >> putStr hLine3 >> putStr hLine4
     >> putStr hLine5 >> putStr hLine6 >> putStr hLine7 >> putStr hLine8
-    >> putStr hLine9 >> putStr hLine10
+    >> putStr hLine9 >> putStr hLine10 >> putStr hLine11
diff --git a/lvtc/app/Main.hs b/lvtc/app/Main.hs
index cb24862..0f41aca 100644
--- a/lvtc/app/Main.hs
+++ b/lvtc/app/Main.hs
@@ -14,9 +14,9 @@ import Run (run)
 import Version (printVersion)
 
 dispatchArgs :: Args -> IO ()
-dispatchArgs (Args Run fPath oFile v) = run (Args Run fPath oFile v)
-dispatchArgs (Args ShowHelp _ _ _) = printHelp
-dispatchArgs (Args ShowVersion _ _ _) = printVersion
+dispatchArgs (Args Run fPath oFile v fs) = run (Args Run fPath oFile v fs)
+dispatchArgs (Args ShowHelp _ _ _ _) = printHelp
+dispatchArgs (Args ShowVersion _ _ _ _) = printVersion
 
 dispatchIfOk :: Either Args String -> IO ()
 dispatchIfOk (Left args) = dispatchArgs args
diff --git a/lvtc/app/Run.hs b/lvtc/app/Run.hs
index 1a454fe..768ccd4 100644
--- a/lvtc/app/Run.hs
+++ b/lvtc/app/Run.hs
@@ -67,6 +67,13 @@ listAllFiles v path =
         p True = putStrLn ("Compiling Folder: " ++ show path)
         p False = return ()
 
+listsAllFiles :: Bool -> [FilePath] -> IO [FilePath]
+listsAllFiles _ [] = return []
+listsAllFiles v (f:fs) =
+    listAllFiles v f
+        >>= (\files -> listsAllFiles v fs
+            >>= (\others -> return (files ++ others)))
+
 getAllFunc :: Bool -> [Expression] -> IO [FuncDeclaration]
 getAllFunc _ [] = return []
 getAllFunc v ((Expression.Function str):expressions) =
@@ -119,10 +126,10 @@ showDebug True wasm = print wasm
 showDebug False _ = return ()
 
 run :: Args -> IO ()
-run (Args Run fPath oFile v) =
+run (Args Run fPath oFile v fPaths) =
     transformedWasm >>= \wasm -> (showDebug v wasm >> writeWasm wasm oFile)
     where
-        expressions = listAllFiles v fPath >>= getFilesExpression v
+        expressions = listsAllFiles v (fPath:fPaths) >>= getFilesExpression v
         funcs = expressions >>= getAllFunc v
         transformedWatLike = transformToWatLike v (checkAst v funcs)
         transformedWat = transformToWat v transformedWatLike
diff --git a/lvtc/src/Lexeme.hs b/lvtc/src/Lexeme.hs
index 083d301..fe8a845 100644
--- a/lvtc/src/Lexeme.hs
+++ b/lvtc/src/Lexeme.hs
@@ -13,6 +13,7 @@ module Lexeme
 replaceN :: Int -> String -> String
 replaceN _ [] = []
 replaceN 0 ('"':xs) = '"' : replaceN 1 xs
+replaceN 1 ('\\':'0':xs) = '\0' : replaceN 1 xs
 replaceN 1 ('\\':'n':xs) = '\n' : replaceN 1 xs
 replaceN 1 ('\\':'t':xs) = '\t' : replaceN 1 xs
 replaceN 1 ('\\':'v':xs) = '\v' : replaceN 1 xs
diff --git a/lvtc/src/ParseLvt.hs b/lvtc/src/ParseLvt.hs
index 74e6667..67a6a7b 100644
--- a/lvtc/src/ParseLvt.hs
+++ b/lvtc/src/ParseLvt.hs
@@ -95,8 +95,8 @@ parseOperatorOp =
     Var
         <$> (parseString "+" <|> parseString "-" <|> parseString "*"
             <|> parseString "/" <|> parseString "{" <|> parseString "}"
-            <|> parseString "==" <|> parseString "!=" <|> parseString "<"
-            <|> parseString ">" <|> parseString "<=" <|> parseString ">=")
+            <|> parseString "==" <|> parseString "!=" <|> parseString "<=" 
+            <|> parseString ">=" <|> parseString "<" <|> parseString ">")
 
 parseOperator' :: ShuntingYardState -> Parser ShuntingYardState
 parseOperator' sys =
diff --git a/lvtc/stdlib/Convert.lvt b/lvtc/stdlib/Convert.lvt
new file mode 100644
index 0000000..b60fbf6
--- /dev/null
+++ b/lvtc/stdlib/Convert.lvt
@@ -0,0 +1,30 @@
+fn intToBool(a: Int) -> Bool
+{
+    if (a == 1)
+    {
+        <- True;
+    };
+    <- False;
+};
+
+fn boolToInt(a: Bool) -> Int
+{
+    if (a)
+    {
+        <- 1;
+    };
+    <- 0;
+};
+
+fn charToInt(a: Char) -> Int
+{
+    @Char i = '\0';
+    @Int res = 0;
+
+    while (i < a)
+    {
+        res = res + 1;
+        i = i + 1;
+    };
+    <- res;
+};
diff --git a/lvtc/stdlib/Logic.lvt b/lvtc/stdlib/Logic.lvt
new file mode 100644
index 0000000..66289a3
--- /dev/null
+++ b/lvtc/stdlib/Logic.lvt
@@ -0,0 +1,40 @@
+fn or(a: Bool, b: Bool) -> Bool
+{
+    if (a)
+    {
+        <- True;
+    };
+    <- b;
+};
+
+fn and(a: Bool, b: Bool) -> Bool
+{
+    if (a)
+    {
+        <- b;
+    };
+    <- False;
+};
+
+fn not(a: Bool) -> Bool
+{
+    if (a)
+    {
+        <- False;
+    };
+    <- True;
+};
+
+fn xor(a: Bool, b: Bool) -> Bool
+{
+    if (a)
+    {
+        <- not(b);
+    };
+    <- b;
+};
+
+fn nand(a: Bool, b: Bool) -> Bool
+{
+    <- not(and(a, b));
+};
diff --git a/lvtc/stdlib/Math.lvt b/lvtc/stdlib/Math.lvt
new file mode 100644
index 0000000..7b734b4
--- /dev/null
+++ b/lvtc/stdlib/Math.lvt
@@ -0,0 +1,57 @@
+fn mod(a: Int, b: Int) -> Int
+{
+    @Int res = a;
+    @Int q = a / b;
+    @Int r = q * b;
+    res = res - r;
+    <- res;
+};
+
+fn square(a: Int) -> Int
+{
+    <- a * a;
+};
+
+fn cube(a: Int) -> Int
+{
+    <- a * a * a;
+};
+
+fn pow(a: Int, b: Int) -> Int
+{
+    @Int res = 1;
+    @Int i = 0;
+
+    while (i < b)
+    {
+        res = res * a;
+        i = i + 1;
+    };
+    <- res;
+};
+
+fn factorial(a: Int) -> Int
+{
+    @Int res = 1;
+    @Int i = 2;
+
+    while (i <= a)
+    {
+        res = res * i;
+        i = i + 1;
+    };
+    <- res;
+};
+
+fn factorialRec(a: Int) -> Int
+{
+    if (a == 0)
+    {
+        <- 1;
+    };
+    if (a == 1)
+    {
+        <- 1;
+    };
+    <- a * factorialRec(a - 1);
+};