diff --git a/CoreHelpers.tl b/CoreHelpers.tl
index 33022b7..24dba75 100644
--- a/CoreHelpers.tl
+++ b/CoreHelpers.tl
@@ -15,6 +15,7 @@ function CoreHelpers.standardInputRefill(): string
 	return input
 end
 
+
 function CoreHelpers._oneReadRefill(str: string): function(): string 
 	local alreadyRead: boolean = false
 	return function(): string
@@ -115,6 +116,14 @@ end
 
 
 
+function CoreHelpers.recNumber(env: Environment)
+	local dataStack = CoreHelpers.getActiveDataStack(env)
+	local token = dataStack:pop() as string
+	if CoreHelpers.isNumber(token) then
+		-- push the XTs onto the stack
+		dataStack:push(true)
+	end
+end
 
 
 return CoreHelpers
diff --git a/CoreWords.tl b/CoreWords.tl
index e165a64..4d320ba 100644
--- a/CoreWords.tl
+++ b/CoreWords.tl
@@ -8,84 +8,83 @@ local defineWord = helpers.defineWord
 local ret = helpers.ret
 local makeCall = helpers.makeCall
 -- Mathematical operations
-local function add(state: Environment)
-  local a, b = popTwoOperands(state)
+local function add(env: Environment)
+  local a, b = popTwoOperands(env)
   if areNumbers(a,b) then
     local c = (a as number) + (b as number)
-    getActiveDataStack(state):push(c)
+    getActiveDataStack(env):push(c)
   else
     error("invalid operands for add operation!")
   end
 end
-local function sub(state: Environment)
-  local a, b = popTwoOperands(state)
+local function sub(env: Environment)
+  local a, b = popTwoOperands(env)
   if areNumbers(a, b) then
     local c = (a as number) - (b as number)
-    getActiveDataStack(state):push(c)
+    getActiveDataStack(env):push(c)
   else
     error("invalid operands for sub operation!")
   end
 end
-local function mul(state: Environment)
-  local a, b = popTwoOperands(state)
+local function mul(env: Environment)
+  local a, b = popTwoOperands(env)
   if areNumbers(a, b) then
     local c = (a as number) * (b as number)
-    getActiveDataStack(state):push(c)
+    getActiveDataStack(env):push(c)
   else
     error("invalid operands for mul operation!")
   end
 end
-local function div(state: Environment)
-  local a, b = popTwoOperands(state)
+local function div(env: Environment)
+  local a, b = popTwoOperands(env)
   if areNumbers(a, b) then
     local c = (a as number) / (b as number)
-    getActiveDataStack(state):push(c)
+    getActiveDataStack(env):push(c)
   else
     error("invalid operands for div operation!")
   end
 end
 
-local function dup(state: Environment)
-  local stack = getActiveDataStack(state)
+local function dup(env: Environment)
+  local stack = getActiveDataStack(env)
   local top = stack:pop()
   stack:push(top)
   stack:push(top)
 end
-local function swap(state: Environment)
-  local stack = getActiveDataStack(state)
-  local a, b = popTwoOperands(state)
+local function swap(env: Environment)
+  local stack = getActiveDataStack(env)
+  local a, b = popTwoOperands(env)
   stack:push(b)
   stack:push(a)
 end
-local function rot(state: Environment)
-  local stack = getActiveDataStack(state)
+local function rot(env: Environment)
+  local stack = getActiveDataStack(env)
   local c, b, a= stack:pop(), stack:pop(), stack:pop()
   stack:push(b)
   stack:push(c)
   stack:push(a)
 end
-local function drop(state: Environment)
-  local stack = getActiveDataStack(state)
+local function drop(env: Environment)
+  local stack = getActiveDataStack(env)
   stack:pop()
 end
-local function over(state: Environment)
-  local stack = getActiveDataStack(state)
+local function over(env: Environment)
+  local stack = getActiveDataStack(env)
   local b, a = stack:pop(), stack:pop()
   stack:push(a)
   stack:push(b)
   stack:push(a)
 end
 -- I/O operations
-local function dot(state: Environment)
-	local out = state.activeDataStack:pop()
+local function dot(env: Environment)
+	local out = env.activeDataStack:pop()
   io.write(tostring(out) as string.."\n")
 end
-local function twoDup(state: Environment)
-  over(state)
-  over(state)
-end
-local function twoSwap(state: Environment)
-  local stack = getActiveDataStack(state)
+
+local twoDup = helpers.makeCall{over, over, ret}
+
+local function twoSwap(env: Environment)
+  local stack = getActiveDataStack(env)
   local d, c, b, a = stack:pop(), stack:pop(), stack:pop(), stack:pop()
   stack:push(c)
   stack:push(d)
@@ -94,8 +93,8 @@ local function twoSwap(state: Environment)
 end
 
 
-local function twoOver(state: Environment)
-  local stack = getActiveDataStack(state)
+local function twoOver(env: Environment)
+  local stack = getActiveDataStack(env)
   local d, c, b, a = stack:pop(), stack:pop(), stack:pop(), stack:pop()
   stack:push(a)
   stack:push(b)
@@ -104,17 +103,16 @@ local function twoOver(state: Environment)
   stack:push(a)
   stack:push(b)
 end
-local function nip(state: Environment)
-  local stack = getActiveDataStack(state)
+local function nip(env: Environment)
+  local stack = getActiveDataStack(env)
   local b, _ = stack:pop(), stack:pop()
   stack:push(b)
 end
-local function tuck(state: Environment)
-  swap(state)
-  over(state)
-end
-local function roll(state: Environment)
-  local stack = getActiveDataStack(state)
+
+local tuck = helpers.makeCall{swap, over, ret}
+
+local function roll(env: Environment)
+  local stack = getActiveDataStack(env)
   local u = stack:pop()
   local bufferStack = Stack:new()
   if u is number then
@@ -136,11 +134,11 @@ local function roll(state: Environment)
     error("u is not a number")
   end
 end 
-local function getExecutionToken(state: Environment)
-  local stack = getActiveDataStack(state)
-  skipWhitespace(state)
-  local name: string = parseToken(state)
-  for _, dictionary in ipairs(state.dictionaries) do
+local function getExecutionToken(env: Environment)
+  local stack = getActiveDataStack(env)
+  skipWhitespace(env)
+  local name: string = parseToken(env)
+  for _, dictionary in ipairs(env.dictionaries) do
     local wordinfo = dictionary:lookup(name)
     if wordinfo then
       stack:push((wordinfo as WordInfo).func)
@@ -149,10 +147,34 @@ local function getExecutionToken(state: Environment)
   end
 end
 
-local function execute(state: Environment)
-  local stack = getActiveDataStack(state)
+local function execute(env: Environment)
+  local stack = getActiveDataStack(env)
   local func: function(Environment) = stack:pop() as function(Environment)
-  func(state)
+  func(env)
+end
+
+local function enterCompileMode(e: Environment)
+  e.compileState = true
+end
+
+local function exitCompileMode(e: Environment)
+  e.compileState = false
+end
+
+local function compile(env: Environment)
+
+end
+local function literal(env: Environment)
+  local stack = env.activeDataStack
+  local fun =  function(e: Environment)
+    
+
+  end
+end
+
+local function postpone(env: Environment)
+
+
 end
 
 local CoreWords = Dictionary:new()
@@ -175,6 +197,8 @@ defineWord(CoreWords, "TUCK", tuck, false)
 defineWord(CoreWords, "ROLL", roll, false)
 defineWord(CoreWords, "'", getExecutionToken, false)
 defineWord(CoreWords, "EXECUTE", execute, false)
+defineWord(CoreWords, "[", exitCompileMode, false)
+defineWord(CoreWords, "]", enterCompileMode, false)
 
 CoreWords:define("+", addInfo)
 CoreWords:define("-", subInfo)
diff --git a/DataStructures.tl b/DataStructures.tl
index c206643..428695e 100644
--- a/DataStructures.tl
+++ b/DataStructures.tl
@@ -38,7 +38,7 @@ local type DataStructures = record
     interrupts: {function(Environment)}
     activeInputStream: InputStream
     dictionaries: {Dictionary}
-    state: boolean
+    compileState: boolean
     new: function(Environment): Environment
     addDataStack: function(Environment, Stack)
     changeCompilerStack: function(Environment, Stack)
diff --git a/tests.lua b/tests.lua
index 445bb8f..f6ab915 100644
--- a/tests.lua
+++ b/tests.lua
@@ -390,6 +390,22 @@ describe("Interpreter tests", function()
             assert.are.equal(3, testEnv.activeDataStack.contents[1])
          end)
       end)
+      describe("[ tests", function()
+         it("Switches the environment's state to interpretation mode.", function()
+            local testEnv = buildEnvironment("[")
+            testEnv.compileState = true
+            interpreters.start(testEnv)
+            assert.are.equal(false, testEnv.compileState)
+         end)
+      end)
+      describe("] tests", function()
+         it("Switches the environment's state to compilation mode.", function()
+            local testEnv = buildEnvironment("]")
+            testEnv.compileState = false
+            interpreters.start(testEnv)
+            assert.are.equal(true, testEnv.compileState)
+         end)
+      end)
    end)
 end)