diff --git a/02-functions/.gitkeep b/02-functions/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/02-functions/Ascii.m b/02-functions/Ascii.m
new file mode 100644
index 0000000..70816b9
--- /dev/null
+++ b/02-functions/Ascii.m
@@ -0,0 +1 @@
+  w "The ASCII code of ""a"" is ",$ascii("a"),".",!
diff --git a/02-functions/Char.m b/02-functions/Char.m
new file mode 100644
index 0000000..e271ba3
--- /dev/null
+++ b/02-functions/Char.m
@@ -0,0 +1,3 @@
+  w "Alphabet: ",!
+  f i=97:1:122 w $char(i)
+  w !
diff --git a/02-functions/Data.m b/02-functions/Data.m
new file mode 100644
index 0000000..11418ce
--- /dev/null
+++ b/02-functions/Data.m
@@ -0,0 +1,26 @@
+  s gtree(1)="Oliver"
+  s gtree(1,1)="James"
+  s gtree(1,1,1)="Harry"
+  s gtree(1,1,2)="Emily"
+  s gtree(1,2)="Amelia"
+  s gtree(1,2,1)="Thomas"
+  s gtree(1,2,2)="Jessica"
+; ...
+  s gtree(1,1,1,1,1)="Robert"
+
+  w "Genealogical tree:",!
+
+  zwrite gtree
+
+; obtain data about a particular node
+; 0, the node does not exist
+; 1, the node exists, has no descendant
+; 10, the node exists, has no data, has descendant
+; 11, the node exists, has data, has descendant
+
+  w !,"Data about a few nodes: ",!
+
+  w "$d(gtree(""foo"")) is ",$d(gtree("foo")),!
+  w "$d(gtree(1,1,1,1,1)) is ",$d(gtree(1,1,1,1,1)),!
+  w "$d(gtree(1,1,1,1)) is ",$d(gtree(1,1,1,1)),!
+  w "$d(gtree(1)) is ",$d(gtree(1)),!
diff --git a/02-functions/Extract.m b/02-functions/Extract.m
new file mode 100644
index 0000000..7a0142c
--- /dev/null
+++ b/02-functions/Extract.m
@@ -0,0 +1,3 @@
+  s string="Hello world!"
+  w "Original string: ",string,!
+  w "Substring: ",$extract(string,1,5),!
diff --git a/06-databases/GenealogicalTree.m b/06-databases/GenealogicalTree.m
deleted file mode 100644
index f966721..0000000
--- a/06-databases/GenealogicalTree.m
+++ /dev/null
@@ -1,57 +0,0 @@
-
-; global array as a tree
-
-  w "Genealogical tree:",!
-
-; create global records
-
-  s ^gtree(0)="Oliver"
-  s ^gtree(0,0)="Jack"
-  s ^gtree(0,1)="Amelia"
-  s ^gtree(0,0,0)="Harry"
-  s ^gtree(0,0,1)="Emily"
-  s ^gtree(0,1,0)="Thomas"
-  s ^gtree(0,1,1)="Jessica"
-  s ^gtree(0,0,0,0)="Michael"
-  s ^gtree(0,0,0,1)="Olivia"
-  s ^gtree(0,0,1,0)="Robert"
-  s ^gtree(0,0,1,1)="Mary"
-  s ^gtree(0,1,0,0)="George"
-  s ^gtree(0,1,0,1)="Susan"
-  s ^gtree(0,1,1,0)="Charles"
-  s ^gtree(0,1,1,1)="Elizabeth"
-; ...
-  s ^gtree(0,0,0,0,0,0)="Thomas"
-
-; TODO: traverse the tree and display information
-; ...
-
-; retrieve a global record
-
-  w "^gtree(0,1,1) is ",^gtree(0,1,1),!
-
-; obtain data about a particular node
-; 0, the node does not exist
-; 1, the node exists, has no descendant
-; 10, the node exists, has no data, has descendant
-; 11, the node exists, has data, has descendant
-
-  w "$data(^gtree(0,2)) is ",$data(^gtree(0,3)),!
-  w "$data(^gtree(0,1,1,1)) is ",$data(^gtree(0,1,1,1)),!
-  w "$data(^gtree(0,0,0,0,0)) is ",$data(^gtree(0,0,0,0,0)),!
-  w "$data(^gtree(0)) is ",$data(^gtree(0)),!
-
-; remove the global array
-; 0, the node does not exist
-; 0, the node does not exist
-; 0, the node does not exist
-; 0, the node does not exist
-
-  w !,"Removing tree...",!
-
-  k ^gtree
-
-  w "$data(^gtree(0,2)) is ",$data(^gtree(0,3)),!
-  w "$data(^gtree(0,1,1,1)) is ",$data(^gtree(0,1,1,1)),!
-  w "$data(^gtree(0,0,0,0,0)) is ",$data(^gtree(0,0,0,0,0)),!
-  w "$data(^gtree(0)) is ",$data(^gtree(0)),!
diff --git a/README.md b/README.md
index f737a5b..2fc1435 100644
--- a/README.md
+++ b/README.md
@@ -157,7 +157,37 @@ Then run the example:
 
 ## 2. Functions
 
-> TODO.
+### [`Ascii.m`](https://github.com/programarivm/mumps-examples/blob/master/02-functions/Ascii.m)
+
+    The ASCII code of "a" is 97.
+
+### [`Char.m`](https://github.com/programarivm/mumps-examples/blob/master/02-functions/Char.m)
+
+    Alphabet:
+    abcdefghijklmnopqrstuvwxyz
+
+### [`Data.m`](https://github.com/programarivm/mumps-examples/blob/master/02-functions/Data.m)
+
+    Genealogical tree:
+    gtree(1)="Oliver"
+    gtree(1,1)="James"
+    gtree(1,1,1)="Harry"
+    gtree(1,1,1,1,1)="Robert"
+    gtree(1,1,2)="Emily"
+    gtree(1,2)="Amelia"
+    gtree(1,2,1)="Thomas"
+    gtree(1,2,2)="Jessica"
+
+    Data about a few nodes:
+    $d(gtree("foo")) is 0
+    $d(gtree(1,1,1,1,1)) is 1
+    $d(gtree(1,1,1,1)) is 10
+    $d(gtree(1)) is 11
+
+### [`Extract.m`](https://github.com/programarivm/mumps-examples/blob/master/02-functions/Extract.m)
+
+    Original string: Hello world!
+    Substring: Hello
 
 ## 3. Utility Routines
 
@@ -196,21 +226,6 @@ Then run the example:
 
 ## 6. Databases
 
-### [`GenealogicalTree.m`](https://github.com/programarivm/mumps-examples/blob/master/06-databases/GenealogicalTree.m)
-
-    Genealogical tree:
-    ^gtree(0,1,1) is Jessica
-    $data(^gtree(0,2)) is 0
-    $data(^gtree(0,1,1,1)) is 1
-    $data(^gtree(0,0,0,0,0)) is 10
-    $data(^gtree(0)) is 11
-
-    Removing tree...
-    $data(^gtree(0,2)) is 0
-    $data(^gtree(0,1,1,1)) is 0
-    $data(^gtree(0,0,0,0,0)) is 0
-    $data(^gtree(0)) is 0
-
 ### [`basic-sql-crud/Main.m`](https://github.com/programarivm/mumps-examples/blob/master/06-databases/basic-sql-crud/Main.m)
 
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