diff --git a/harm/cli.py b/harm/cli.py
new file mode 100644
index 0000000..1b6637e
--- /dev/null
+++ b/harm/cli.py
@@ -0,0 +1,222 @@
+from memory_Context import *
+from llm import *
+
+# Exit
+#
+# Conditions:
+# 1. `e`, `exit`, `q`, or `quit` was entered
+# 2. Victory has just been reported
+@llm_by_value
+def cli_exit(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "input" and
+    (
+      c.input == "e" or
+      c.input == "exit" or
+      c.input == "q" or
+      c.input == "quit"
+    )
+  ):
+    c.exit = True
+    c.recentField = "exit"
+    return c
+  #}
+  if (
+    c.recentField == "outputVictory"
+  ):
+    c.exit = True
+    c.recentField = "exit"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Ask user to go on
+#
+# Conditions:
+# 1. Items have just matched and there are still items left to select
+@llm_by_value
+def cli_goOn(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "outputMatchedItems" and
+    len(c.hiddenItems) != len(c.playfieldItems)
+  ):
+    c.outputGoOn = "Go on:"
+    c.recentField = "outputGoOn"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Greet the user
+#
+# Conditions:
+# 1. Just launched
+@llm_by_value
+def cli_greetUser(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "didLaunch" and
+    c.didLaunch == True
+  ):
+    c.outputGreeting = "OGS Memory Command Line Interface"
+    c.recentField = "outputGreeting"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Ask user to select second item to have a pair of selected items
+#
+# Conditions:
+# 1. Single item has just been selected
+@llm_by_value
+def cli_promptSecondItemSelection(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 1
+  ):
+    c.outputPromptSelection = "Select the second item now:"
+    c.recentField = "outputPromptSelection"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Report matched items
+#
+# Conditions:
+# 1. Items were hidden (i.e., they matched)
+@llm_by_value
+def cli_reportMatchedItems(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "hiddenItems"
+  ):
+    c.outputMatchedItems = "Items matched!"
+    c.recentField = "outputMatchedItems"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Report victory
+@llm_by_value
+def cli_reportVictory(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "victory"
+  ):
+    c.outputVictory = "VICTORY! The game is over now"
+    c.recentField = "outputVictory"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Select item
+#
+# Conditions:
+# 1. Id is digit
+@llm_by_value
+def cli_selectItem(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "input" and
+    llm_isDigit(c.input)
+  ):
+    # CLI ids start with 1 while memory module has ids starting with 0
+    # Convert CLI id to memory id
+    c.selectedId = llm_strToInt(c.input) - 1
+    c.recentField = "selectedId"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Show help (aka commands)
+#
+# Conditions:
+# 1. Just launched
+# 1. `h` or `help` was entered
+@llm_by_value
+def cli_showHelp(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    (
+      c.recentField == "didLaunch" and
+      c.didLaunch == True
+    ) or
+    (
+      c.recentField == "input" and
+      c.input == "h"
+    ) or
+    (
+      c.recentField == "input" and
+      c.input == "help"
+    )
+  ):
+    c.outputHelp = "Commands:\n\te, exit, q, quit\n\t\tExit\n\th, help\n\t\tList commands\n\t1, 2, 3, ...\n\t\tSelect item\nEnter your choice:"
+    c.recentField = "outputHelp"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Report mismatched items
+@llm_by_value
+def cli_reportMismatchedItems(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "mismatchedItems"
+  ):
+    c.outputMismatchedItems = "Wrong! Try again:"
+    c.recentField = "outputMismatchedItems"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+## Report selection of invalid item ids
+##
+## Conditions:
+## 1. Index out of bounds: less than minimum
+## 2. Index out of bounds: greater than maximum
+## 3. Item is already hidden
+##@llm_by_value
+##def cli_shouldReportInvalidItemSelection(
+##  c: cli_Context
+##) -> cli_Context:
+##  if (
+##    c.recentField == "cMemory" and
+##    c.cMemory.recentField == "selectedItems" and
+##    len(c.cMemory.selectedItems) == 1
+##  ):
+##    c.outputPromptSelection = "Select the second item now:"
+##    c.recentField = "outputPromptSelection"
+##    return c
+##  #}
+##  c.recentField = "none"
+##  return c
+###}
diff --git a/harm/cli_test.py b/harm/cli_test.py
new file mode 100644
index 0000000..9aaafdc
--- /dev/null
+++ b/harm/cli_test.py
@@ -0,0 +1,303 @@
+from cli import *
+from memory import *
+from memory_Context import *
+
+def cli_test_exit_e(
+) -> str:
+  c = memory_createContext()
+  c.input = "e"
+  c.recentField = "input"
+  c = cli_exit(c)
+  if (
+    c.recentField == "exit"
+  ):
+    return "OK: cli_exit_e"
+  #}
+  return "ERR: cli_exit_e"
+#}
+
+def cli_test_exit_exit(
+) -> str:
+  c = memory_createContext()
+  c.input = "exit"
+  c.recentField = "input"
+  c = cli_exit(c)
+  if (
+    c.recentField == "exit"
+  ):
+    return "OK: cli_exit_exit"
+  #}
+  return "ERR: cli_exit_e"
+#}
+
+def cli_test_exit_victory(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Match the first pair of tiles.
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "2"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+
+  # Match the second pair of tiles.
+  c.input = "3"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "4"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+  c = memory_detectVictory(c)
+  c = cli_reportVictory(c)
+  c = cli_exit(c)
+
+  if (
+    c.recentField == "exit"
+  ):
+    return "OK: cli_exit_victory"
+  #}
+  return "ERR: cli_exit_victory"
+#}
+
+def cli_test_exit_q(
+) -> str:
+  c = memory_createContext()
+  c.input = "q"
+  c.recentField = "input"
+  c = cli_exit(c)
+  if (
+    c.recentField == "exit"
+  ):
+    return "OK: cli_exit_q"
+  #}
+  return "ERR: cli_exit_q"
+#}
+
+def cli_test_exit_quit(
+) -> str:
+  c = memory_createContext()
+  c.input = "quit"
+  c.recentField = "input"
+  c = cli_exit(c)
+  if (
+    c.recentField == "exit"
+  ):
+    return "OK: cli_exit_quit"
+  #}
+  return "ERR: cli_exit_quit"
+#}
+
+def cli_test_goOn(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Match the first pair of items.
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "2"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+  c = cli_reportMatchedItems(c)
+
+  c = cli_goOn(c)
+  if (
+    c.recentField == "outputGoOn"
+  ):
+    return "OK: cli_goOn"
+  #}
+  return "ERR: cli_goOn"
+#}
+
+def cli_test_greetUser(
+) -> str:
+  c = memory_createContext()
+  c.didLaunch = True
+  c.recentField = "didLaunch"
+  c = cli_greetUser(c)
+  if (
+    c.recentField == "outputGreeting"
+  ):
+    return "OK: cli_greetUser"
+  #}
+  return "ERR: cli_greetUser"
+#}
+
+def cli_test_promptSecondItemSelection(
+) -> str:
+  c = memory_createContext()
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = cli_promptSecondItemSelection(c)
+  if (
+    c.recentField == "outputPromptSelection"
+  ):
+    return "OK: cli_promptSecondItemSelection"
+  #}
+  return "ERR: cli_promptSecondItemSelection"
+#}
+
+def cli_test_reportMatchedItems(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "2"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+  c = cli_reportMatchedItems(c)
+  if (
+    c.recentField == "outputMatchedItems"
+  ):
+    return "OK: cli_reportMatchedItems"
+  #}
+  return "ERR: cli_reportMatchedItems"
+#}
+
+def cli_test_reportMismatchedItems(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "3"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_detectMismatchedItems(c)
+  c = cli_reportMismatchedItems(c)
+  if (
+    c.recentField == "outputMismatchedItems"
+  ):
+    return "OK: cli_reportMismatchedItems"
+  #}
+  return "ERR: cli_reportMismatchedItems"
+#}
+
+def cli_test_selectItem(
+) -> str:
+  c = memory_createContext()
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  if (
+    c.recentField == "selectedId" and
+    c.selectedId == 0
+  ):
+    return "OK: cli_selectItem"
+  #}
+  return "ERR: cli_selectItem"
+#}
+
+def cli_test_showHelp_h(
+) -> str:
+  c = memory_createContext()
+  c.input = "h"
+  c.recentField = "input"
+  c = cli_showHelp(c)
+  if (
+    c.recentField == "outputHelp"
+  ):
+    return "OK: cli_showHelp_h"
+  #}
+  return "ERR: cli_showHelp_h"
+#}
+
+def cli_test_showHelp_help(
+) -> str:
+  c = memory_createContext()
+  c.input = "help"
+  c.recentField = "input"
+  c = cli_showHelp(c)
+  if (
+    c.recentField == "outputHelp"
+  ):
+    return "OK: cli_showHelp_help"
+  #}
+  return "ERR: cli_showHelp_help"
+#}
+
+def cli_test_reportVictory(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Match the first pair of tiles.
+  c.input = "1"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "2"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+
+  # Match the second pair of tiles.
+  c.input = "3"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c.input = "4"
+  c.recentField = "input"
+  c = cli_selectItem(c)
+  c = memory_selectItem(c)
+  c = memory_hideMatchingItems(c)
+  c = memory_detectVictory(c)
+  c = cli_reportVictory(c)
+
+  if (
+    c.recentField == "outputVictory"
+  ):
+    return "OK: cli_reportVictory"
+  #}
+  return "ERR: cli_reportVictory"
+#}
+
+#def cli_test_shouldReportIvalidItemSelection_outOfBoundsMin(
+#) -> str:
+#  c = cli_createContext()
+#  c.cMemory = memory_createContext()
+#  c.input = "0"
+#  c = cli_selectItem(c)
+#  c = cli_shouldReportInvalidItemSelection(c)
+#  if (
+#    c.recentField == "outputInvalidItemSelection"
+#  ):
+#    return "OK: cli_shouldReportInvalidItemSelection"
+#  #}
+#  return "ERR: cli_shouldReportInvalidItemSelection"
+##}
+#
diff --git a/harm/ctx.py b/harm/ctx.py
new file mode 100644
index 0000000..af8f36e
--- /dev/null
+++ b/harm/ctx.py
@@ -0,0 +1,53 @@
+import copy
+
+class ctx_Controller:
+  def __init__(self, c):
+    self.callbacks = []
+    self.context = c
+    self.functions = []
+    self.isProcessingQueue = False
+    self.queue = []
+  
+  def executeFunctions(self):
+    c = self.queue.pop(0)
+    for f in self.functions:
+      ctx = f(c)
+      if ctx.recentField != "none":
+        self.queue.append(ctx)
+
+    self.context.recentField = c.recentField
+    self.context.setField(c.recentField, c.field(c.recentField))
+    self.reportContext()
+
+  def processQueue(self):
+    # Decline recursion.
+    if self.isProcessingQueue:
+      return
+    self.isProcessingQueue = True
+    while len(self.queue) > 0:
+      self.executeFunctions()
+    self.isProcessingQueue = False
+
+  def registerCallback(self, cb):
+    self.callbacks.append(cb)
+
+  def registerFieldCallback(self, fieldName, cb):
+    self.callbacks.append(lambda c: cb(c) if c.recentField == fieldName else None)
+
+  def registerFunction(self, f):
+    self.functions.append(f)
+
+  def registerFunctions(self, funcs):
+    for f in funcs:
+      self.functions.append(f)
+
+  def reportContext(self):
+    for cb in self.callbacks:
+      cb(self.context)
+
+  def set(self, fieldName, value):
+    c = copy.deepcopy(self.context)
+    c.setField(fieldName, value)
+    c.recentField = fieldName
+    self.queue.append(c)
+    self.processQueue()
diff --git a/harm/ctx_test2.py b/harm/ctx_test2.py
new file mode 100644
index 0000000..74720c8
--- /dev/null
+++ b/harm/ctx_test2.py
@@ -0,0 +1,142 @@
+from ctx import *
+from memory import *
+from memory_Context import *
+
+def ctx_test_Controller_executeFunctions_registerFunction_set(
+) -> str:
+  c = memory_createContext()
+  ctrl = ctx_Controller(c)
+  # Disable automatic invocation of executeFunctions.
+  ctrl.isProcessingQueue = True
+  ctrl.set("input", "123")
+
+  @llm_by_value
+  def processInput(c):
+    if (
+      c.recentField == "input"
+    ):
+      c.outputHelp = "Checked"
+      c.recentField = "outputHelp"
+      return c
+    #}
+    c.recentField = "none"
+    return c
+  #}
+
+  ctrl.registerFunction(processInput)
+  # Apply 'input'.
+  ctrl.executeFunctions()
+  # Apply 'outputHelp'.
+  ctrl.executeFunctions()
+  if (
+    c.input == "123" and
+    c.outputHelp == "Checked"
+  ):
+    return "OK: ctx_Controller_executeFunctions_set"
+  #}
+  return "ERR: ctx_Controller_executeFunctions_set"
+#}
+
+def ctx_test_Controller_processQueue(
+) -> str:
+  c = memory_createContext()
+  ctrl = ctx_Controller(c)
+
+  @llm_by_value
+  def processInput(c):
+    if (
+      c.recentField == "input"
+    ):
+      c.outputHelp = "Checked"
+      c.recentField = "outputHelp"
+      return c
+    #}
+    c.recentField = "none"
+    return c
+  #}
+
+  ctrl.registerFunction(processInput)
+  ctrl.set("input", "abc");
+  if (
+    c.input == "abc" and
+    c.outputHelp == "Checked"
+  ):
+    return "OK: ctx_Controller_processQueue"
+  #}
+  return "ERR: ctx_Controller_processQueue"
+#}
+
+def ctx_test_Controller_registerFieldCallback_match(
+) -> str:
+  c = memory_createContext()
+  ctrl = ctx_Controller(c)
+  c.input = "123"
+  c.recentField = "input"
+  
+  globals()["callbackInput"] = ""
+  def setCallbackInput(c):
+    if (
+      c.recentField == "input"
+    ):
+      globals()["callbackInput"] = c.input
+
+  ctrl.registerFieldCallback("input", setCallbackInput)
+  ctrl.reportContext()
+  if (
+    c.input == globals()["callbackInput"]
+  ):
+    return "OK: ctx_Controller_registerFieldCallback_match"
+  #}
+  return "ERR: ctx_Controller_registerFieldCallback_match"
+#}
+
+def ctx_test_Controller_registerFieldCallback_mismatch(
+) -> str:
+  c = memory_createContext()
+  ctrl = ctx_Controller(c)
+  c.input = "123"
+  c.outputHelp = "you"
+  # A field other than 'input' is marked recent.
+  c.recentField = "outputHelp"
+
+  globals()["callbackInput"] = ""
+  def setCallbackInput(c):
+    if (
+      c.recentField == "input"
+    ):
+      globals()["callbackInput"] = c.input
+
+  ctrl.registerFieldCallback("input", setCallbackInput)
+  ctrl.reportContext()
+  if (
+    globals()["callbackInput"] == ""
+  ):
+    return "OK: ctx_Controller_registerFieldCallback_mismatch"
+  #}
+  return "ERR: ctx_Controller_registerFieldCallback_mismatch"
+#}
+
+def ctx_test_memoryContext_field(
+) -> str:
+  c = memory_createContext()
+  c.input = "abc"
+  if (
+    c.field("input") == "abc"
+  ):
+    return "OK: ctx_memoryContext_field"
+  #}
+  return "ERR: ctx_memoryContext_field"
+#}
+
+def ctx_test_memoryContext_setField(
+) -> str:
+  c = memory_createContext()
+  c.input = "abc"
+  c.setField("input", "123")
+  if (
+    c.input == "123"
+  ):
+    return "OK: ctx_memoryContext_setField"
+  #}
+  return "ERR: ctx_memoryContext_setField"
+#}
diff --git a/harm/desktop.py b/harm/desktop.py
new file mode 100644
index 0000000..98ee3f5
--- /dev/null
+++ b/harm/desktop.py
@@ -0,0 +1,317 @@
+import arcade
+from gui_aux import *
+from desktop_Platform import *
+
+def desktop_createDesc(p):
+  p.desc = arcade.Sprite()
+  p.descSprites.append(p.desc)
+  p.desc.texture = p.descTextures[0]
+  # Position.
+  pos = gui_aux_cellScreenPosition(p.c, p.c.descPosition)
+  p.desc.left = pos[0]
+  p.desc.top = pos[1]
+  # Invisible by default.
+  p.desc.visible = False
+#}
+
+def desktop_createDeselectedTiles(p):
+  for (id, pos) in enumerate(p.c.tilePositions):
+    tile = arcade.AnimatedTimeBasedSprite()
+    p.deselectedTiles.append(tile)
+    p.deselectedSprites.append(tile)
+
+    tile.guid = id
+    tile.texture = p.textures[0]
+    # Animation between two textures.
+    a1 = arcade.sprite.AnimationKeyframe(0, 700, p.textures[0])
+    a2 = arcade.sprite.AnimationKeyframe(1, 700, p.textures[1])
+    tile.frames.append(a1)
+    tile.frames.append(a2)
+    # Position.
+    tile.left = pos[0]
+    tile.top = pos[1]
+  #}
+#}
+
+def desktop_createSelectedTiles(p):
+  for (id, pos) in enumerate(p.c.tilePositions):
+    tile = arcade.Sprite()
+    p.selectedTiles.append(tile)
+    p.selectedSprites.append(tile)
+
+    tile.guid = id
+    tile.texture = p.textures[2 + p.c.playfieldItems[id]]
+    # Position.
+    tile.left = pos[0]
+    tile.top = pos[1]
+    # Invisible by default.
+    tile.visible = False
+  #}
+#}
+
+def desktop_createSplash(p):
+  p.splash = arcade.Sprite()
+  p.splashSprites.append(p.splash)
+  p.splash.texture = p.splashTextures[0]
+  # Position.
+  pos = gui_aux_cellScreenPosition(p.c, [0, 0])
+  p.splash.left = pos[0]
+  p.splash.top = pos[1]
+#}
+
+def desktop_createTitle(p):
+  p.title = arcade.Sprite()
+  p.titleSprites.append(p.title)
+  p.title.texture = p.titleTextures[0]
+  # Position.
+  pos = gui_aux_cellScreenPosition(p.c, p.c.titlePosition)
+  p.title.left = pos[0]
+  p.title.top = pos[1]
+  # Invisible by default.
+  p.title.visible = False
+#}
+
+# Deselect mismatched tiles
+#
+# Conditions:
+# 1. Time to deselect mismatched items
+def desktop_deselectMismatchedTiles(p):
+  if (
+    p.c.recentField == "deselectMismatchedTiles"
+  ):
+    for id in p.c.mismatchedItems:
+      p.deselectedTiles[id].visible = True
+      p.selectedTiles[id].visible = False
+    #}
+  #}
+#}
+
+# Display description for the first selected tile
+#
+# Conditions:
+# 1. tile has just been selected and it's the first one in pair
+def desktop_displayDesc(p):
+  if (
+    p.c.recentField == "selectedId" and
+    (
+      len(p.c.selectedItems) == 0 or
+      len(p.c.selectedItems) == 2
+    )
+  ):
+    gid = p.c.playfieldItems[p.c.selectedId]
+    p.desc.texture = p.descTextures[gid]
+    p.desc.visible = True
+  #}
+#}
+
+# Display ending splash screen
+#
+# Conditions:
+# 1. Time to display victory screen
+def desktop_displayEndingSplashScreen(p):
+  if (
+    p.c.recentField == "displayEndingSplashScreen"
+  ):
+    p.splash.texture = p.splashTextures[1]
+    p.splash.visible = True
+  #}
+#}
+
+# Hide deselected tile and show selected one
+#
+# Conditions:
+# 1. tile has just been selected
+def desktop_displaySelectedTile(p):
+  if (
+    p.c.recentField == "selectedId"
+  ):
+    id = p.c.selectedId
+    p.deselectedTiles[id].visible = False
+    p.selectedTiles[id].visible = True
+  #}
+#}
+
+# Display title for the first selected tile
+#
+# Conditions:
+# 1. tile has just been selected and it's the first one in pair
+def desktop_displayTitle(p):
+  if (
+    p.c.recentField == "selectedId" and
+    (
+      len(p.c.selectedItems) == 0 or
+      len(p.c.selectedItems) == 2
+    )
+  ):
+    gid = p.c.playfieldItems[p.c.selectedId]
+    p.title.texture = p.titleTextures[gid]
+    p.title.visible = True
+  #}
+#}
+
+# Hide beginning splash screen
+#
+# Conditions:
+# 1. Time to hide
+def desktop_hideBeginningSplashScreen(p):
+  if (
+    p.c.recentField == "hideBeginningSplashScreen"
+  ):
+    p.splash.visible = False
+  #}
+#}
+
+# Hide description
+#
+# Conditions:
+# 1. tiles has been mismatched or timed out to to hide after matching
+def desktop_hideDesc(p):
+  if (
+    p.c.recentField == "hideMatchingTiles" or
+    p.c.recentField == "mismatchedItems"
+  ):
+    p.desc.visible = False
+  #}
+#}
+
+# Hide matching tiles
+#
+# Conditions:
+# 1. Time to hide matching items
+def desktop_hideMatchingTiles(p):
+  if (
+    p.c.recentField == "hideMatchingTiles"
+  ):
+    for id in p.c.selectedItems:
+      p.deselectedTiles[id].visible = False
+      p.selectedTiles[id].visible = False
+    #}
+  #}
+#}
+
+# Hide title
+#
+# Conditions:
+# 1. tiles has been mismatched or timed out to to hide after matching
+def desktop_hideTitle(p):
+  if (
+    p.c.recentField == "hideMatchingTiles" or
+    p.c.recentField == "mismatchedItems"
+  ):
+    p.title.visible = False
+  #}
+#}
+
+# Load description textures
+def desktop_loadDescTextures(p):
+  texs = []
+  for (id, td) in enumerate(p.c.descTextureDescriptions):
+    tex = arcade.load_texture(
+      td.fileName,
+      x = td.x,
+      y = td.y,
+      width = td.width,
+      height = td.height
+    )
+    texs.append(tex)
+  #}
+  p.descTextures = texs
+#}
+
+# Load beginning and ending textures
+def desktop_loadSplashTextures(p):
+  texs = []
+  for (id, td) in enumerate(p.c.splashTextureDescriptions):
+    tex = arcade.load_texture(
+      td.fileName,
+      x = td.x,
+      y = td.y,
+      width = td.width,
+      height = td.height
+    )
+    texs.append(tex)
+    print(f"desktop_loadST: '{tex}'")
+  #}
+  p.splashTextures = texs
+#}
+
+# Load tile textures
+def desktop_loadTextures(p):
+  texs = []
+  for (id, td) in enumerate(p.c.textureDescriptions):
+    tex = arcade.load_texture(
+      td.fileName,
+      x = td.x,
+      y = td.y,
+      width = td.width,
+      height = td.height
+    )
+    texs.append(tex)
+  #}
+  p.textures = texs
+#}
+
+# Load tiTLe textures
+def desktop_loadTitleTextures(p):
+  texs = []
+  for (id, td) in enumerate(p.c.titleTextureDescriptions):
+    tex = arcade.load_texture(
+      td.fileName,
+      x = td.x,
+      y = td.y,
+      width = td.width,
+      height = td.height
+    )
+    texs.append(tex)
+  #}
+  p.titleTextures = texs
+#}
+
+# Postpone deselection of mismatched tiles for better UX
+#
+# Conditions:
+# 1. a pair of tiles has been mismatched
+def desktop_scheduleDeselectionOfMismatchedTiles(p):
+  if (
+    p.c.recentField == "mismatchedItems"
+  ):
+    p.sequentialTimer.schedule("deselectMismatchedTiles", True, p.c.deselectMismatchedTilesDelay)
+  #}
+#}
+
+# Postpone display of the ending splash screen
+#
+# Conditions:
+# 1. just finished removing all tiles
+def desktop_scheduleDisplayOfEndingSplashScreen(p):
+  if (
+    p.c.recentField == "victory"
+  ):
+    p.sequentialTimer.schedule("displayEndingSplashScreen", True, p.c.splashEndDelay)
+  #}
+#}
+
+# Postpone hiding of matching tiles for better UX
+#
+# Conditions:
+# 1. a pair of tiles has been matched
+def desktop_scheduleHidingOfMatchingTiles(p):
+  if (
+    p.c.recentField == "hiddenItems"
+  ):
+    p.sequentialTimer.schedule("hideMatchingTiles", True, p.c.hideMatchingTilesDelay)
+  #}
+#}
+
+# Postpone hiding of the beginning splash screen
+#
+# Conditions:
+# 1. just launched the game
+def desktop_scheduleHidingOfBeginningSplashScreen(p):
+  if (
+    p.c.recentField == "splashBeginTimeout"
+  ):
+    p.sequentialTimer.schedule("hideBeginningSplashScreen", True, p.c.splashBeginTimeout)
+  #}
+#}
+
diff --git a/harm/desktop_Platform.py b/harm/desktop_Platform.py
new file mode 100644
index 0000000..b796232
--- /dev/null
+++ b/harm/desktop_Platform.py
@@ -0,0 +1,22 @@
+import arcade
+
+class desktop_Platform:
+  def __init__(self):
+    self.c = None
+    self.ctrl = None
+    self.desc = None
+    self.descSprites = arcade.SpriteList()
+    self.descTextures = []
+    self.deselectedSprites = arcade.SpriteList()
+    self.deselectedTiles = []
+    self.mousePosition = []
+    self.selectedTiles = []
+    self.sequentialTimer = None
+    self.selectedSprites = arcade.SpriteList()
+    self.splash = None
+    self.splashSprites = arcade.SpriteList()
+    self.splashTextures = []
+    self.textures = []
+    self.title = None
+    self.titleSprites = arcade.SpriteList()
+    self.titleTextures = []
diff --git a/harm/desktop_SequentialTimer.py b/harm/desktop_SequentialTimer.py
new file mode 100644
index 0000000..f4708b9
--- /dev/null
+++ b/harm/desktop_SequentialTimer.py
@@ -0,0 +1,35 @@
+import time
+
+class desktop_SequentialTimer():
+  def __init__(self):
+    self.activeTimeout = None
+    self.callback = None
+    self.queue = []
+  #}
+
+  def update(self):
+    # Get current time in milliseconds.
+    now = time.time_ns() // 1000000
+
+    # Schedule an item.
+    if (
+      self.activeTimeout == None and
+      len(self.queue) > 0
+    ):
+      self.activeTimeout = now + self.queue[0][0]
+    elif (
+      self.activeTimeout != None and
+      now >= self.activeTimeout
+    ):
+      # Report when the time is up.
+      key = self.queue[0][1]
+      value = self.queue[0][2]
+      self.queue.pop(0)
+      self.activeTimeout = None
+      self.callback(key, value)
+    #}
+  #}
+
+  def schedule(self, key, value, timeout):
+    self.queue.append([timeout, key, value])
+  #}
diff --git a/harm/desktop_Window.py b/harm/desktop_Window.py
new file mode 100644
index 0000000..8ca4165
--- /dev/null
+++ b/harm/desktop_Window.py
@@ -0,0 +1,32 @@
+import arcade
+from desktop_aux import *
+
+class desktop_Window(arcade.Window):
+  def __init__(self, p):
+    super().__init__(
+      p.c.windowWidth,
+      p.c.windowHeight,
+      p.c.windowTitle,
+    )
+    self.antialiasing = p.c.windowAntialiasing
+    self.background_color = arcade.color_from_hex_string(p.c.windowBackgroundColor)
+    self.p = p
+
+  def on_draw(self):
+    arcade.start_render()
+    self.p.descSprites.draw()
+    self.p.deselectedSprites.draw()
+    self.p.selectedSprites.draw()
+    self.p.splashSprites.draw()
+    self.p.titleSprites.draw()
+
+  def on_mouse_press(self, x, y, button, key_modifiers):
+    id = desktop_aux_tileIdAt(self.p, x, y)
+    if (
+      id != None
+    ):
+      self.p.ctrl.set("selectedId", id)
+
+  def on_update(self, delta):
+    self.p.deselectedSprites.update_animation()
+    self.p.sequentialTimer.update()
diff --git a/harm/desktop_aux.py b/harm/desktop_aux.py
new file mode 100644
index 0000000..de994b5
--- /dev/null
+++ b/harm/desktop_aux.py
@@ -0,0 +1,13 @@
+import arcade
+
+# Find a visible tile id at the specified location
+def desktop_aux_tileIdAt(p, x, y):
+  sprites = arcade.get_sprites_at_point([x, y], p.deselectedSprites)
+  if (
+    len(sprites) != 0 and
+    sprites[0].visible
+  ):
+    return sprites[0].guid
+  #}
+  return None
+#}
diff --git a/harm/gui.py b/harm/gui.py
new file mode 100644
index 0000000..c5560b4
--- /dev/null
+++ b/harm/gui.py
@@ -0,0 +1,175 @@
+from gui_aux import *
+from gui_TextureDescription import *
+from llm import *
+from memory_Context import *
+
+# Generate texture descriptions for harm description
+#
+# Conditions:
+# 1.descImage, descImageCount, descImageHeight, or descImageWidth has just changed
+@llm_by_value
+def gui_generateDescTextureDescriptions(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "descImage" or
+    c.recentField == "descImageCount" or
+    c.recentField == "descImageHeight" or
+    c.recentField == "descImageWidth"
+  ):
+    tds: list[gui_TextureDescription] = []
+    for id in range(0, c.descImageCount):
+      td = gui_createTextureDescription()
+      td.fileName = c.descImage
+      td.height = c.descImageHeight
+      td.width = c.descImageWidth
+      td.x = id * c.descImageWidth
+      td.y = 0
+      tds.append(td)
+    #}
+    c.descTextureDescriptions = tds
+    c.recentField = "descTextureDescriptions"
+    return c
+  #}
+
+  c.recentField = "none"
+  return c
+#}
+
+# Generate texture descriptions for splash screens
+#
+# Conditions:
+# 1.splashImage, splashImageCount, splashImageHeight, or splashImageWidth has just changed
+@llm_by_value
+def gui_generateSplashTextureDescriptions(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "splashImage" or
+    c.recentField == "splashImageCount" or
+    c.recentField == "splashImageHeight" or
+    c.recentField == "splashImageWidth"
+  ):
+    tds: list[gui_TextureDescription] = []
+    for id in range(0, c.splashImageCount):
+      td = gui_createTextureDescription()
+      td.fileName = c.splashImage
+      td.height = c.splashImageHeight
+      td.width = c.splashImageWidth
+      td.x = id * c.splashImageWidth
+      td.y = 0
+      tds.append(td)
+    #}
+    c.splashTextureDescriptions = tds
+    c.recentField = "splashTextureDescriptions"
+    return c
+  #}
+
+  c.recentField = "none"
+  return c
+#}
+
+# Generate texture descriptions for tiles
+#
+# Conditions:
+# 1. tileImage or tileImageCount or tileImageHeight or tileImageWidth has just changed
+@llm_by_value
+def gui_generateTextureDescriptions(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "tileImage" or
+    c.recentField == "tileImageCount" or
+    c.recentField == "tileImageHeight" or
+    c.recentField == "tileImageWidth"
+  ):
+    tds: list[gui_TextureDescription] = []
+    for id in range(0, c.tileImageCount):
+      td = gui_createTextureDescription()
+      td.fileName = c.tileImage
+      td.height = c.tileImageHeight
+      td.width = c.tileImageWidth
+      td.x = id * c.tileImageWidth
+      td.y = 0
+      tds.append(td)
+    #}
+    c.textureDescriptions = tds
+    c.recentField = "textureDescriptions"
+    return c
+  #}
+
+  c.recentField = "none"
+  return c
+#}
+
+# Generate tile positions
+#
+# Conditions:
+# 1. cellSize, playField, windowHeight, or windowWidth has changed and none of them is zero
+@llm_by_value
+def gui_generateTilePositions(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    (
+      c.recentField != "cellPositions" and
+      c.recentField != "cellSize" and
+      c.recentField != "playfieldSize" and
+      c.recentField != "windowHeight" and
+      c.recentField != "windowWidth"
+    ) or
+    (
+      len(c.cellPositions) == 0 or
+      c.cellSize == 0 or
+      c.playfieldSize == 0 or
+      c.windowHeight == 0 or
+      c.windowWidth == 0
+    )
+  ):
+    c.recentField = "none"
+    return c
+  #}
+
+  ps = []
+  for i in range(0, len(c.cellPositions)):
+    p = gui_aux_cellScreenPosition(c, c.cellPositions[i])
+    ps.append(p)
+  #}
+
+  c.tilePositions = ps
+  c.recentField = "tilePositions"
+  return c
+#}
+
+# Generate texture descriptions for tiTLes
+#
+# Conditions:
+# 1. titleImage, titleImageCount, titleImageHeight, or titleImageWidth has just changed
+@llm_by_value
+def gui_generateTitleTextureDescriptions(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "titleImage" or
+    c.recentField == "titleImageCount" or
+    c.recentField == "titleImageHeight" or
+    c.recentField == "titleImageWidth"
+  ):
+    tds: list[gui_TextureDescription] = []
+    for id in range(0, c.titleImageCount):
+      td = gui_createTextureDescription()
+      td.fileName = c.titleImage
+      td.height = c.titleImageHeight
+      td.width = c.titleImageWidth
+      td.x = id * c.titleImageWidth
+      td.y = 0
+      tds.append(td)
+    #}
+    c.titleTextureDescriptions = tds
+    c.recentField = "titleTextureDescriptions"
+    return c
+  #}
+
+  c.recentField = "none"
+  return c
+#}
diff --git a/harm/gui_TextureDescription.py b/harm/gui_TextureDescription.py
new file mode 100644
index 0000000..ea15a43
--- /dev/null
+++ b/harm/gui_TextureDescription.py
@@ -0,0 +1,15 @@
+class gui_TextureDescription:
+  def __init__(self):
+    self.fileName = ""
+    self.height = 0
+    self.width = 0
+    self.x = 0
+    self.y = 0
+  def __repr__(self):
+    return self.__str__()
+
+  def __str__(self):
+    return f"gui_TextureD(fileN/height/width/x/y: '{self.fileName}'/'{self.height}'/'{self.width}'/'{self.x}'/'{self.y}')"
+
+def gui_createTextureDescription():
+  return gui_TextureDescription()
diff --git a/harm/gui_aux.py b/harm/gui_aux.py
new file mode 100644
index 0000000..970fbeb
--- /dev/null
+++ b/harm/gui_aux.py
@@ -0,0 +1,78 @@
+from memory_Context import *
+
+# Generate grid positions in cell dimensions
+#
+# Conditions:
+# 1. 2x2 grid
+# 2. 4x4 grid
+def gui_aux_cellGridPositions(
+  size: int
+) -> [[int]]:
+  if (
+    size == 2
+  ):
+    return [
+      [14, 7],
+      [19, 7],
+      [14, 13],
+      [19, 13],
+    ]
+  #}
+
+  if (
+    size == 4
+  ):
+    return [
+      [9, 1],
+      [14, 1],
+      [19, 1],
+      [24, 1],
+
+      [9, 7],
+      [14, 7],
+      [19, 7],
+      [24, 7],
+
+      [9, 13],
+      [14, 13],
+      [19, 13],
+      [24, 13],
+
+      [9, 19],
+      [14, 19],
+      [19, 19],
+      [24, 19],
+    ]
+  #}
+#}
+
+# Generate positions in cell dimensions for Harm game
+def gui_aux_cellHarmPositions(
+) -> [[int]]:
+  return [
+    [4, 6],
+    [9, 6],
+    [14, 6],
+    [19, 6],
+    [24, 6],
+    [29, 6],
+
+    [4, 12],
+    [9, 12],
+    [14, 12],
+
+    [4, 18],
+    [9, 18],
+    [14, 18],
+  ]
+#}
+
+# Convert cell position to screen position
+def gui_aux_cellScreenPosition(
+  c: memory_Context,
+  pos: [int]
+) -> [int]:
+  x = pos[0] * c.cellSize
+  y = c.windowHeight - pos[1] * c.cellSize
+  return [x, y]
+#}
diff --git a/harm/gui_aux_test.py b/harm/gui_aux_test.py
new file mode 100644
index 0000000..393ed94
--- /dev/null
+++ b/harm/gui_aux_test.py
@@ -0,0 +1,15 @@
+from gui_aux import *
+
+def test_gui_aux_cellGridPositions(
+) -> str:
+  items2x2 = gui_aux_cellGridPositions(2)
+  items4x4 = gui_aux_cellGridPositions(4)
+
+  if (
+    len(items2x2) == 4 and
+    len(items4x4) == 16
+  ):
+    return "OK: gui_aux_cellGridPositions"
+  #}
+  return "ERR: gui_aux_cellGridPositions"
+#}
diff --git a/harm/gui_test.py b/harm/gui_test.py
new file mode 100644
index 0000000..fcad14f
--- /dev/null
+++ b/harm/gui_test.py
@@ -0,0 +1,49 @@
+from gui import *
+from gui_TextureDescription import *
+from memory_Context import *
+
+def test_gui_generateTextureDescriptions(
+) -> str:
+  c = memory_createContext()
+  c.tileImage = "res/img.png"
+  c.tileImageCount = 3
+  c.tileImageHeight = 35
+  c.tileImageWidth = 20
+  c.recentField = "tileImageWidth"
+  c = gui_generateTextureDescriptions(c)
+  if (
+    c.recentField == "textureDescriptions" and
+    len(c.textureDescriptions) == 3 and
+    c.textureDescriptions[0].fileName == "res/img.png" and
+    c.textureDescriptions[0].height == 35 and
+    c.textureDescriptions[0].width == 20 and
+    c.textureDescriptions[0].x == 0 and
+    c.textureDescriptions[1].x == 20 and
+    c.textureDescriptions[2].x == 40
+  ):
+    return "OK: gui_generateTextureDescriptions"
+  #}
+  return "ERR: gui_generateTextureDescriptions"
+#}
+
+def test_gui_generateTilePositions(
+) -> str:
+  c = memory_createContext()
+
+  c.cellSize = 10
+  c.playfieldSize = 2
+  c.cellPositions = gui_aux_cellGridPositions(c.playfieldSize)
+  c.windowHeight = 200
+  c.windowWidth = 200
+  c.recentField = "windowWidth"
+
+  c = gui_generateTilePositions(c)
+  if (
+    c.recentField == "tilePositions" and
+    len(c.tilePositions) == 4 and
+    c.tilePositions[0][0] == 140
+  ):
+    return "OK: gui_generateTilePositions"
+  #}
+  return "ERR: gui_generateTilePositions"
+#}
diff --git a/harm/llm.py b/harm/llm.py
new file mode 100644
index 0000000..0ca860f
--- /dev/null
+++ b/harm/llm.py
@@ -0,0 +1,22 @@
+import copy
+
+# Make deep copies of arguments to treat the arguments as structs.
+# https://stackoverflow.com/a/15398021
+def llm_by_value(f):
+  def _f(*args, **kwargs):
+      argsCopy = copy.deepcopy(args)
+      kwargsCopy = copy.deepcopy(kwargs)
+      return f(*argsCopy, **kwargsCopy)
+  return _f
+
+# Tell if string is a digit
+def llm_isDigit(s):
+  return s.isdigit()
+
+# Tell if string starts with certain prefix.
+def llm_startsWith(s, prefix):
+  return s.startswith(prefix)
+
+# Convert string to integer
+def llm_strToInt(s):
+  return int(s)
diff --git a/harm/llm_test.py b/harm/llm_test.py
new file mode 100644
index 0000000..17ee0ca
--- /dev/null
+++ b/harm/llm_test.py
@@ -0,0 +1,31 @@
+from llm import *
+
+def llm_test_isDigit_digit(
+) -> str:
+  if (
+    llm_isDigit("123")
+  ):
+    return "OK: llm_isDigit_digit"
+  #}
+  return "ERR: llm_isDigit_digit"
+#}
+
+def llm_test_isDigit_notDigit(
+) -> str:
+  if (
+    llm_isDigit("abc")
+  ):
+    return "ERR: llm_isDigit_notDigit"
+  #}
+  return "OK: llm_isDigit_notDigit"
+#}
+
+def llm_test_strToInt(
+) -> str:
+  if (
+    llm_strToInt("123") == 123
+  ):
+    return "OK: llm_strToInt"
+  #}
+  return "ERR: llm_strToInt"
+#}
diff --git a/harm/llm_test_Python.py b/harm/llm_test_Python.py
new file mode 100644
index 0000000..8c0e39c
--- /dev/null
+++ b/harm/llm_test_Python.py
@@ -0,0 +1,21 @@
+from llm import *
+from memory_Context import *
+
+def llm_test_Python_copyByValue(
+) -> str:
+  c = memory_createContext()
+  c.input = "abc"
+
+  @llm_by_value
+  def alterValue(c):
+    c.input = "alteredValue"
+
+  alterValue(c)
+
+  if (
+    c.input == "abc"
+  ):
+    return "OK: llm_Python_copyByValue"
+  #}
+  return "ERR: llm_Python_copyByValue"
+#}
diff --git a/harm/main-gui.py b/harm/main-gui.py
new file mode 100644
index 0000000..a23a229
--- /dev/null
+++ b/harm/main-gui.py
@@ -0,0 +1,160 @@
+import arcade
+from cli import *
+from cli_test import *
+from ctx import *
+from ctx_test2 import *
+from desktop import *
+from desktop_Platform import *
+from desktop_SequentialTimer import *
+from desktop_Window import *
+from gui import *
+from gui_aux import *
+from gui_aux_test import *
+from gui_test import *
+from llm_test import *
+from llm_test_Python import *
+from memory_test import *
+import sys
+
+print(ctx_test_Controller_executeFunctions_registerFunction_set())
+print(ctx_test_Controller_processQueue())
+print(ctx_test_Controller_registerFieldCallback_match())
+print(ctx_test_Controller_registerFieldCallback_mismatch())
+print(ctx_test_memoryContext_field())
+print(ctx_test_memoryContext_setField())
+
+print(llm_test_Python_copyByValue())
+print(llm_test_isDigit_digit())
+print(llm_test_isDigit_notDigit())
+print(llm_test_strToInt())
+
+print(memory_test_detectMismatchedItems())
+print(memory_test_detectMismatchedItems_itemTwice())
+print(memory_test_detectVictory())
+print(memory_test_generateConstPlayfield())
+print(memory_test_hideMatchingItems())
+print(memory_test_selectItem_1x())
+print(memory_test_selectItem_2x())
+print(memory_test_selectItem_3x())
+
+print(cli_test_exit_e())
+print(cli_test_exit_exit())
+print(cli_test_exit_victory())
+print(cli_test_exit_q())
+print(cli_test_exit_quit())
+print(cli_test_goOn())
+print(cli_test_greetUser())
+print(cli_test_showHelp_h())
+print(cli_test_showHelp_help())
+print(cli_test_selectItem())
+print(cli_test_promptSecondItemSelection())
+print(cli_test_reportMatchedItems())
+print(cli_test_reportMismatchedItems())
+print(cli_test_reportVictory())
+
+print(test_gui_aux_cellGridPositions())
+print(test_gui_generateTextureDescriptions())
+print(test_gui_generateTilePositions())
+
+ctrl = ctx_Controller(memory_createContext())
+ctrl.registerFunctions([
+#  cli_exit,
+#  cli_goOn,
+#  cli_greetUser,
+#  cli_promptSecondItemSelection,
+#  cli_reportMatchedItems,
+#  cli_reportMismatchedItems,
+#  cli_reportVictory,
+#  cli_selectItem,
+#  cli_showHelp,
+  gui_generateDescTextureDescriptions,
+  gui_generateSplashTextureDescriptions,
+  gui_generateTextureDescriptions,
+  gui_generateTilePositions,
+  gui_generateTitleTextureDescriptions,
+  memory_detectMismatchedItems,
+  memory_detectVictory,
+  memory_generateConstPlayfield,
+  memory_hideMatchingItems,
+  memory_selectItem,
+])
+
+def printDbg(c):
+  print(f"Dbg key/value: '{c.recentField}'/'{c.field(c.recentField)}'")
+ctrl.registerCallback(printDbg)
+ctrl.registerFieldCallback("exit", lambda c: sys.exit(0))
+
+p = desktop_Platform()
+p.ctrl = ctrl
+p.sequentialTimer = desktop_SequentialTimer()
+p.sequentialTimer.callback = lambda key, value: ctrl.set(key, value)
+
+# Bind platform to context changes.
+def process(c):
+  # Copy context to platform.
+  p.c = c
+  # Perform context dependent calls of desktop functions.
+  # Similar to context functions, but no platform is returned.
+  desktop_deselectMismatchedTiles(p)
+  desktop_displayDesc(p)
+  desktop_displayEndingSplashScreen(p)
+  desktop_displaySelectedTile(p)
+  desktop_displayTitle(p)
+  desktop_hideBeginningSplashScreen(p)
+  desktop_hideDesc(p)
+  desktop_hideMatchingTiles(p)
+  desktop_hideTitle(p)
+  desktop_scheduleDisplayOfEndingSplashScreen(p)
+  desktop_scheduleHidingOfBeginningSplashScreen(p)
+  desktop_scheduleHidingOfMatchingTiles(p)
+  desktop_scheduleDeselectionOfMismatchedTiles(p)
+ctrl.registerCallback(process)
+
+ctrl.set("didLaunch", True)
+ctrl.set("playfieldSize", 6)
+
+ctrl.set("cellPositions", gui_aux_cellHarmPositions())
+ctrl.set("cellSize", 25)
+ctrl.set("deselectMismatchedTilesDelay", 500)
+ctrl.set("descImage", "res/harm.png")
+ctrl.set("descImageCount", 6)
+ctrl.set("descImageHeight", 250)
+ctrl.set("descImageWidth", 375)
+ctrl.set("descPosition", [19, 12])
+ctrl.set("hideMatchingTilesDelay", 500)
+ctrl.set("splashBeginTimeout", 2000)
+ctrl.set("splashEndDelay", 100)
+ctrl.set("splashImage", "res/splash.png")
+ctrl.set("splashImageCount", 2)
+ctrl.set("splashImageHeight", 600)
+ctrl.set("splashImageWidth", 900)
+ctrl.set("tileImage", "res/harmful-tiles.png")
+ctrl.set("tileImageCount", 8)
+ctrl.set("tileImageHeight", 100)
+ctrl.set("tileImageWidth", 75)
+ctrl.set("titleImage", "res/harmful-titles.png")
+ctrl.set("titleImageCount", 6)
+ctrl.set("titleImageHeight", 100)
+ctrl.set("titleImageWidth", 700)
+ctrl.set("titlePosition", [4, 1])
+ctrl.set("windowWidth", 900)
+ctrl.set("windowHeight", 600)
+ctrl.set("windowAntialiasing", False)
+ctrl.set("windowBackgroundColor", "#ffffff")
+ctrl.set("windowTitle", "Вредные продукты")
+
+desktop_loadTextures(p)
+desktop_createDeselectedTiles(p)
+desktop_createSelectedTiles(p)
+
+desktop_loadTitleTextures(p)
+desktop_createTitle(p)
+
+desktop_loadDescTextures(p)
+desktop_createDesc(p)
+
+desktop_loadSplashTextures(p)
+desktop_createSplash(p)
+
+wnd = desktop_Window(p)
+arcade.run()
diff --git a/harm/main.py b/harm/main.py
new file mode 100644
index 0000000..e3fdb56
--- /dev/null
+++ b/harm/main.py
@@ -0,0 +1,77 @@
+from cli import *
+from cli_test import *
+from ctx import *
+from ctx_test2 import *
+#from ctx_test import *
+#from ctx_test_Python import *
+from llm_test import *
+from llm_test_Python import *
+from memory_test import *
+import sys
+
+print(ctx_test_Controller_executeFunctions_registerFunction_set())
+print(ctx_test_Controller_processQueue())
+print(ctx_test_Controller_registerFieldCallback_match())
+print(ctx_test_Controller_registerFieldCallback_mismatch())
+print(ctx_test_memoryContext_field())
+print(ctx_test_memoryContext_setField())
+
+print(llm_test_Python_copyByValue())
+print(llm_test_isDigit_digit())
+print(llm_test_isDigit_notDigit())
+print(llm_test_strToInt())
+
+print(memory_test_detectMismatchedItems())
+print(memory_test_detectMismatchedItems_itemTwice())
+print(memory_test_detectVictory())
+print(memory_test_generateConstPlayfield())
+print(memory_test_hideMatchingItems())
+print(memory_test_selectItem_1x())
+print(memory_test_selectItem_2x())
+print(memory_test_selectItem_3x())
+
+print(cli_test_exit_e())
+print(cli_test_exit_exit())
+print(cli_test_exit_victory())
+print(cli_test_exit_q())
+print(cli_test_exit_quit())
+print(cli_test_goOn())
+print(cli_test_greetUser())
+print(cli_test_showHelp_h())
+print(cli_test_showHelp_help())
+print(cli_test_selectItem())
+print(cli_test_promptSecondItemSelection())
+print(cli_test_reportMatchedItems())
+print(cli_test_reportMismatchedItems())
+print(cli_test_reportVictory())
+
+ctrl = ctx_Controller(memory_createContext())
+ctrl.registerFunctions([
+  cli_exit,
+  cli_goOn,
+  cli_greetUser,
+  cli_promptSecondItemSelection,
+  cli_reportMatchedItems,
+  cli_reportMismatchedItems,
+  cli_reportVictory,
+  cli_selectItem,
+  cli_showHelp,
+  memory_detectMismatchedItems,
+  memory_detectVictory,
+  memory_generateConstPlayfield,
+  memory_hideMatchingItems,
+  memory_selectItem,
+])
+
+def printOutput(c):
+  if c.recentField.startswith("output"):
+    print(c.field(c.recentField))
+ctrl.registerCallback(printOutput)
+ctrl.registerFieldCallback("exit", lambda c: sys.exit(0))
+
+ctrl.set("didLaunch", True)
+ctrl.set("playfieldSize", 2)
+
+for line in sys.stdin:
+  ln = line.rstrip()
+  ctrl.set("input", ln)
diff --git a/harm/memory.py b/harm/memory.py
new file mode 100644
index 0000000..e929d44
--- /dev/null
+++ b/harm/memory.py
@@ -0,0 +1,138 @@
+from memory_Context import *
+from llm import *
+
+# Detect mismatched items
+#
+# Conditions:
+# 0. Two items has just been selected
+# 1. The same item has been selected twice
+# 2. Selected items are of different groups
+@llm_by_value
+def memory_detectMismatchedItems(
+  c: memory_Context
+) -> memory_Context:
+  if not (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 2
+  ):
+    c.recentField = "none"
+    return c
+  #}
+  if (
+    c.selectedItems[0] == c.selectedItems[1]
+  ):
+    c.mismatchedItems.clear()
+    c.mismatchedItems.append(c.selectedItems[0])
+    c.recentField = "mismatchedItems"
+    return c
+  #}
+  if (
+    c.playfieldItems[c.selectedItems[0]] != c.playfieldItems[c.selectedItems[1]]
+  ):
+    c.mismatchedItems.clear()
+    c.mismatchedItems.append(c.selectedItems[0])
+    c.mismatchedItems.append(c.selectedItems[1])
+    c.recentField = "mismatchedItems"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Detect victory
+#
+# Conditions:
+# 1. Matching items have just been hidden and all items are hidden now
+@llm_by_value
+def memory_detectVictory(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "hiddenItems" and
+    len(c.hiddenItems) == len(c.playfieldItems)
+  ):
+    c.victory = True
+    c.recentField = "victory"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Generate constant playfield
+#
+# Conditions:
+# 1. Size has just been specified
+#
+# Both ids and group ids start with 0
+@llm_by_value
+def memory_generateConstPlayfield(
+  c: memory_Context
+) -> memory_Context:
+  if not (
+    c.recentField == "playfieldSize"
+  ):
+    c.recentField = "none"
+    return c
+  #}
+
+  idGroups: dict[int, int] = { }
+  id = 0
+  for gid in range(0, c.playfieldSize):
+    idGroups[id] = gid
+    id += 1
+    idGroups[id] = gid
+    id += 1
+  #}
+  c.playfieldItems = idGroups
+  c.recentField = "playfieldItems"
+  return c
+#}
+
+# Hide matching selected items
+#
+# Conditions:
+# 1. Two items are selected and they are of the same group
+@llm_by_value
+def memory_hideMatchingItems(
+  c: memory_Context
+) -> memory_Context:
+  if (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 2 and
+    c.playfieldItems[c.selectedItems[0]] == c.playfieldItems[c.selectedItems[1]]
+  ):
+    c.hiddenItems.append(c.selectedItems[0])
+    c.hiddenItems.append(c.selectedItems[1])
+    c.recentField = "hiddenItems"
+    return c
+  #}
+  c.recentField = "none"
+  return c
+#}
+
+# Select item
+#
+# Conditions:
+# 1. Id has just been specified for selection
+@llm_by_value
+def memory_selectItem(
+  c: memory_Context
+) -> memory_Context:
+  if not (
+    c.recentField == "selectedId"
+  ):
+    c.recentField = "none"
+    return c
+  #}
+
+  if (
+    len(c.selectedItems) == 2
+  ):
+    c.selectedItems.clear()
+  #}
+  c.selectedItems.append(c.selectedId)
+  c.recentField = "selectedItems"
+  return c
+#}
+
diff --git a/harm/memory_Context.py b/harm/memory_Context.py
new file mode 100644
index 0000000..ea646c4
--- /dev/null
+++ b/harm/memory_Context.py
@@ -0,0 +1,71 @@
+class memory_Context:
+  def __init__(self):
+    self.cellPositions = []
+    self.cellSize = 0
+    self.descImage = ""
+    self.descImageCount = 0
+    self.descImageHeight = 0
+    self.descImageWidth = 0
+    self.descPosition = []
+    self.descTextureDescriptions = []
+    self.deselectMismatchedTiles = False
+    self.deselectMismatchedTilesDelay = 0
+    self.didLaunch = False
+    self.displayEndingSplashScreen = False
+    self.exit = False
+    self.hiddenItems = []
+    self.hideBeginningSplashScreen = False
+    self.hideMatchingTiles = False
+    self.hideMatchingTilesDelay = 0
+    self.input = ""
+    self.mismatchedItems = []
+    self.outputGoOn = ""
+    self.outputGreeting = ""
+    self.outputHelp = ""
+    self.outputMatchedItems = ""
+    self.outputMismatchedItems = ""
+    self.outputPromptSelection = ""
+    self.outputVictory = ""
+    self.playfieldItems = {}
+    self.playfieldSize = 0
+    self.recentField = "none"
+    self.selectedId = -1
+    self.selectedItems = []
+    self.splashBeginTimeout = 0
+    self.splashEndDelay = 0
+    self.splashImage = ""
+    self.splashImageCount = 0
+    self.splashImageHeight = 0
+    self.splashImageWidth = 0
+    self.textureDescriptions = []
+    self.tileImage = ""
+    self.tileImageCount = 0
+    self.tileImageHeight = 0
+    self.tileImageWidth = 0
+    self.tilePositions = []
+    self.titleImage = ""
+    self.titleImageCount = 0
+    self.titleImageHeight = 0
+    self.titleImageWidth = 0
+    self.titlePosition = []
+    self.titleTextureDescriptions = []
+    self.windowBackgroundColor = "#000000"
+    self.windowHeight = 0
+    self.windowTitle = ""
+    self.windowWidth = 0
+    self.victory = False
+
+  def field(self, fieldName):
+    return getattr(self, fieldName)
+
+  def setField(self, fieldName, value):
+    setattr(self, fieldName, value)
+
+  def __repr__(self):
+    return self.__str__()
+
+  def __str__(self):
+    return f"memory_Context(playfieldI/playfieldS/recentF/selectedId/selectedI: '{self.playfieldItems}'/'{self.playfieldSize}'/'{self.recentField}'/'{self.selectedId}'/'{self.selectedItems}')"
+
+def memory_createContext():
+  return memory_Context()
diff --git a/harm/memory_test.py b/harm/memory_test.py
new file mode 100644
index 0000000..faa79ee
--- /dev/null
+++ b/harm/memory_test.py
@@ -0,0 +1,231 @@
+from memory import *
+from memory_Context import *
+
+def memory_test_detectMismatchedItems(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select two items of different groups.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 2
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # Detect mismatching.
+  c = memory_detectMismatchedItems(c)
+
+  # See if the two selected items do not match.
+  if (
+    c.recentField == "mismatchedItems" and
+    len(c.mismatchedItems) == 2 and
+    c.mismatchedItems[0] == 0 and
+    c.mismatchedItems[1] == 2
+  ):
+    return "OK: memory_detectMismatchedItems"
+  #}
+  return "ERR: memory_detectMismatchedItems"
+#}
+
+def memory_test_detectMismatchedItems_itemTwice(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select the same item twice.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # Detect mismatching.
+  c = memory_detectMismatchedItems(c)
+
+  # See if the two selected items do not match.
+  if (
+    c.recentField == "mismatchedItems" and
+    len(c.mismatchedItems) == 1 and
+    c.mismatchedItems[0] == 0
+  ):
+    return "OK: memory_detectMismatchedItems_itemTwice"
+  #}
+  return "ERR: memory_detectMismatchedItems_itemTwice"
+#}
+
+def memory_test_detectVictory(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select the first two items of the same group.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 1
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # Hide the first pair.
+  c = memory_hideMatchingItems(c)
+
+  # Select the last two items of the same group.
+  c.selectedId = 2
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 3
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # Hide the second pair.
+  c = memory_hideMatchingItems(c)
+
+  # Detect victory.
+  c = memory_detectVictory(c)
+
+  # See if victory has been detected.
+  if (
+    c.recentField == "victory" and
+    c.victory == True
+  ):
+    return "OK: memory_detectVictory"
+  #}
+  return "ERR: memory_detectVictory"
+#}
+
+def memory_test_generateConstPlayfield(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+  if (
+    c.recentField == "playfieldItems" and
+    len(c.playfieldItems) == 4 and
+    c.playfieldItems[0] == 0 and
+    c.playfieldItems[1] == 0 and
+    c.playfieldItems[2] == 1 and
+    c.playfieldItems[3] == 1
+  ):
+    return "OK: memory_generateConstPlayfield"
+  #}
+  return "ERR: memory_generateConstPlayfield"
+#}
+
+def memory_test_hideMatchingItems(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select two items of the same group.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 1
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # Hide matching items.
+  c = memory_hideMatchingItems(c)
+
+  # See if the two selected items match.
+  if (
+    c.recentField == "hiddenItems" and
+    len(c.hiddenItems) == 2 and
+    c.hiddenItems[0] == 0 and
+    c.hiddenItems[1] == 1
+  ):
+    return "OK: memory_hideMatchingItems"
+  #}
+  return "ERR: memory_hideMatchingItems"
+#}
+
+def memory_test_selectItem_1x(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select the first item.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # See if it's in selectedItems now.
+  if (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 1 and
+    c.selectedItems[0] == 0
+  ):
+    return "OK: memory_selectItem_1x"
+  #}
+  return "ERR: memory_selectItem_1x"
+#}
+
+def memory_test_selectItem_2x(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select the first two items.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 1
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # See if both items are selected now.
+  if (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 2 and
+    c.selectedItems[0] == 0 and
+    c.selectedItems[1] == 1
+  ):
+    return "OK: memory_selectItem_2x"
+  #}
+  return "ERR: memory_selectItem_2x"
+#}
+
+def memory_test_selectItem_3x(
+) -> str:
+  c = memory_createContext()
+  c.playfieldSize = 2
+  c.recentField = "playfieldSize"
+  c = memory_generateConstPlayfield(c)
+
+  # Select three items.
+  c.selectedId = 0
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 1
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+  c.selectedId = 2
+  c.recentField = "selectedId"
+  c = memory_selectItem(c)
+
+  # See if only one (last) item is selected now.
+  if (
+    c.recentField == "selectedItems" and
+    len(c.selectedItems) == 1 and
+    c.selectedItems[0] == 2
+  ):
+    return "OK: memory_selectItem_3x"
+  #}
+  return "ERR: memory_selectItem_3x"
+#}
diff --git a/harm/res/harm.png b/harm/res/harm.png
new file mode 100644
index 0000000..8a09d25
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+#!/bin/bash
+/Users/mk/py3.12venv/bin/python3.12 main-gui.py