diff --git a/anagrams.tlv b/anagrams.tlv
index 22c4685..a1fde54 100644
--- a/anagrams.tlv
+++ b/anagrams.tlv
@@ -207,7 +207,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original
@@ -336,7 +336,7 @@
     >  if #l == 0 then return {prefix} end
     >  local result = {}
     >  for _, elem in ipairs(l) do
-    >    result[#result+1] = prefix..elem
+    >    table.insert(result, prefix..elem)
     >  end
     >  return result
     >end
diff --git a/break.tlv b/break.tlv
index 6a67653..92fbeb7 100644
--- a/break.tlv
+++ b/break.tlv
@@ -237,7 +237,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original
@@ -625,11 +625,11 @@
   update:
     >function update(window)
     >  local key = string.char(window:getch())
-    >  local nwords = #program.lines[1].words
     >  if key == ' ' then
-    >    program.lines[1].words[nwords+1] = {data='', cursor=0}
+    >    table.insert(program.lines[1].words, {data='', cursor=0})
     >  else
-    >    program.lines[1].words[nwords].data = program.lines[1].words[nwords].data .. key
+    >    local words = program.lines[1].words
+    >    words[#words].data = words[#words].data .. key
     >  end
     >end
 - __teliva_timestamp:
@@ -682,11 +682,11 @@
     >Thu Mar 17 21:43:20 2022
   update:
     >function update(window, program, key)
-    >  local nwords = #program.lines[1].words
     >  if key == ' ' then
-    >    program.lines[1].words[nwords+1] = {data='', cursor=0}
+    >    table.insert(program.lines[1].words, {data='', cursor=0})
     >  else
-    >    program.lines[1].words[nwords].data = program.lines[1].words[nwords].data .. key
+    >    local words = program.lines[1].words
+    >    words[#words].data = words[#words].data .. key
     >  end
     >end
 - __teliva_timestamp:
diff --git a/graphviz.tlv b/graphviz.tlv
index 941610e..9a5a776 100644
--- a/graphviz.tlv
+++ b/graphviz.tlv
@@ -237,7 +237,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original
@@ -814,7 +814,7 @@
     >  local result = {}
     >  for source, _ in pairs(Graph) do
     >    if not is_target[source] then
-    >      result[#result+1] = source
+    >      table.insert(result, source)
     >    end
     >  end
     >  return result
diff --git a/life.tlv b/life.tlv
index 96f5451..7680093 100644
--- a/life.tlv
+++ b/life.tlv
@@ -237,7 +237,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original
diff --git a/template.tlv b/template.tlv
index 70a4a24..c335e31 100644
--- a/template.tlv
+++ b/template.tlv
@@ -237,7 +237,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original
diff --git a/zet.tlv b/zet.tlv
index decce6d..7248970 100644
--- a/zet.tlv
+++ b/zet.tlv
@@ -237,7 +237,7 @@
     >-- concatenate list 'elems' into 'l', modifying 'l' in the process
     >function append(l, elems)
     >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
+    >    table.insert(l, elems[i])
     >  end
     >end
 - __teliva_timestamp: original