diff --git a/doc/tutorial/basics/Readme.md b/doc/tutorial/basics/Readme.md
index fa0deb7..3628a43 100644
--- a/doc/tutorial/basics/Readme.md
+++ b/doc/tutorial/basics/Readme.md
@@ -30,7 +30,7 @@
   - [Aliases](aliases.md)
   - [Emit Values](emit.md)
   - [Hidden Values](hidden.md)
-- Types and Values
+- Types ~~and~~ are Values
   - [Duplicate Fields](duplicates.md)
   - [Bottom / Error](bottom.md)
   - [Basic Types](types.md)
@@ -42,6 +42,7 @@
   - [Ranges](ranges.md)
   - [Predefined Ranges](rangedef.md)
   - [Lists](lists.md)
+  - [Templates](templates.md)
 - [Modules, Packages, and Instances](instances.md)
   - [Packages](packages.md)
   - [Imports](imports.md)
@@ -52,6 +53,6 @@
   - [List Comprehensions](listcomp.md)
   - [Field Comprehensions](fieldcomp.md)
   - [Conditional Fields](conditional.md)
-  - [Null or Error coalescing](coalescing.md)
+  - [Null or Error coalescing](coalesce.md)
   <!-- - Conversions -->
   <!-- - Functions (simulating) -->
diff --git a/doc/tutorial/basics/bottom.md b/doc/tutorial/basics/bottom.md
index 6a6ac5d..77be74b 100644
--- a/doc/tutorial/basics/bottom.md
+++ b/doc/tutorial/basics/bottom.md
@@ -1,15 +1,16 @@
 [TOC](Readme.md) [Prev](duplicates.md) [Next](types.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Bottom
 
-Specifying duplicate fields with conflicting values results in an error,
-denoted `_|_`.
-
-Technically speaking, bottom is just a value like any other.
-But for all practical purposes it is okay to think of the bottom value
-as an error.
+Specifying duplicate fields with conflicting values results in an error
+or bottom.
+_Bottom_ is a special value in CUE, denoted `_|_`, that indicates an
+error such as incompatible values.
+Any error in CUE results in `_|_`.
+Logically all errors are equal, although errors may be associated with
+metadata such as an error message.
 
 Note that an error is different from `null`: `null` is a valid JSON value,
 whereas `_|_` is not.
@@ -21,10 +22,15 @@
 
 l: [ 1, 2 ]
 l: [ 1, 3 ]
+
+list: [0, 1, 2]
+val: list[3]
 ```
 
 <!-- result -->
 ```
-a: _|_
-l: _|_
+a:    _|_
+l:    _|_
+list: [0, 1, 2]
+val:  _|_
 ```
\ No newline at end of file
diff --git a/doc/tutorial/basics/coalesce.md b/doc/tutorial/basics/coalesce.md
index 41fbfce..3a487a0 100644
--- a/doc/tutorial/basics/coalesce.md
+++ b/doc/tutorial/basics/coalesce.md
@@ -11,12 +11,20 @@
 In the example the fallback values are specified
 for `a` and `b` in case the list index is out of bounds.
 
+To do actual null coalescing one can unify a result with the desired type
+to force an error.
+In that case the default will be used if either the lookup fails or
+the result is not of the desired type.
+
 <!-- CUE editor -->
 ```
 list: [ "Cat", "Mouse", "Dog" ]
 
 a: list[0] | "None"
 b: list[5] | "None"
+
+n: [null]
+v: n[0] & string | "default"
 ```
 
 <!-- result -->
@@ -25,4 +33,6 @@
 
 a: "Cat"
 b: "None"
+n: [null]
+v: "default"
 ```
\ No newline at end of file
diff --git a/doc/tutorial/basics/defaults.md b/doc/tutorial/basics/defaults.md
index 642e621..a46825d 100644
--- a/doc/tutorial/basics/defaults.md
+++ b/doc/tutorial/basics/defaults.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](disjunctions.md) [Next](disjstruct.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Default Values
 
diff --git a/doc/tutorial/basics/disjstruct.md b/doc/tutorial/basics/disjstruct.md
index e60b63b..5cbc9ac 100644
--- a/doc/tutorial/basics/disjstruct.md
+++ b/doc/tutorial/basics/disjstruct.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](defaults.md) [Next](numbers.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Disjunctions of Structs
 
diff --git a/doc/tutorial/basics/disjunctions.md b/doc/tutorial/basics/disjunctions.md
index f9507ce..e049321 100644
--- a/doc/tutorial/basics/disjunctions.md
+++ b/doc/tutorial/basics/disjunctions.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](unification.md) [Next](defaults.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Disjunctions
 
diff --git a/doc/tutorial/basics/duplicates.md b/doc/tutorial/basics/duplicates.md
index 63509d9..7d754cf 100644
--- a/doc/tutorial/basics/duplicates.md
+++ b/doc/tutorial/basics/duplicates.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](hidden.md) [Next](bottom.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Duplicate Fields
 
diff --git a/doc/tutorial/basics/fieldcomp.md b/doc/tutorial/basics/fieldcomp.md
index dfb37d8..6723413 100644
--- a/doc/tutorial/basics/fieldcomp.md
+++ b/doc/tutorial/basics/fieldcomp.md
@@ -17,7 +17,7 @@
 
 {
     "\( strings.ToLower(v) )": {
-        pos:     k
+        pos:     k + 1
         name:    v
         nameLen: len(v)
     } for k, v in a
diff --git a/doc/tutorial/basics/fieldname.md b/doc/tutorial/basics/fieldname.md
index 66da5a3..ab33ac9 100644
--- a/doc/tutorial/basics/fieldname.md
+++ b/doc/tutorial/basics/fieldname.md
@@ -16,6 +16,7 @@
 {
     one: 1,
     two: 2,
+
     "two-and-a-half": 2.5
 }
 ```
diff --git a/doc/tutorial/basics/foldany.md b/doc/tutorial/basics/foldany.md
index 1bcab41..b933eb2 100644
--- a/doc/tutorial/basics/foldany.md
+++ b/doc/tutorial/basics/foldany.md
@@ -6,7 +6,7 @@
 
 This also works if a struct has more than one member.
 
-In general, any JSON configuration can be expressed as a collection of
+In general, any JSON object can be expressed as a collection of
 path-leaf pairs without using any curly braces.
 
 <!-- CUE editor -->
diff --git a/doc/tutorial/basics/instances.md b/doc/tutorial/basics/instances.md
index 1b99949..55a65ff 100644
--- a/doc/tutorial/basics/instances.md
+++ b/doc/tutorial/basics/instances.md
@@ -1,4 +1,4 @@
-[TOC](Readme.md) [Prev](lists.md) [Next](packages.md)
+[TOC](Readme.md) [Prev](templates.md) [Next](packages.md)
 
 # Modules, Packages, and Instances
 
@@ -8,8 +8,6 @@
 A `package` clause allows a single configuration to be split across multiple
 files.
 
-[Packages tutorial](packages.md)
-
 ## Instances
 
 All files within a directory hierarchy with the same package identifier belong
diff --git a/doc/tutorial/basics/lists.md b/doc/tutorial/basics/lists.md
index d077a06..f583308 100644
--- a/doc/tutorial/basics/lists.md
+++ b/doc/tutorial/basics/lists.md
@@ -1,6 +1,6 @@
-[TOC](Readme.md) [Prev](ranges.md) [Next](instances.md)
+[TOC](Readme.md) [Prev](rangedef.md) [Next](templates.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Lists
 
diff --git a/doc/tutorial/basics/numbers.md b/doc/tutorial/basics/numbers.md
index 32f07a4..442d626 100644
--- a/doc/tutorial/basics/numbers.md
+++ b/doc/tutorial/basics/numbers.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](defaults.md) [Next](ranges.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Numbers
 
diff --git a/doc/tutorial/basics/rangedef.md b/doc/tutorial/basics/rangedef.md
index a854b6b..39da35b 100644
--- a/doc/tutorial/basics/rangedef.md
+++ b/doc/tutorial/basics/rangedef.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](ranges.md) [Next](lists.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Predefined Ranges
 
diff --git a/doc/tutorial/basics/ranges.md b/doc/tutorial/basics/ranges.md
index 6ef0efb..c37ea75 100644
--- a/doc/tutorial/basics/ranges.md
+++ b/doc/tutorial/basics/ranges.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](numbers.md) [Next](rangedef.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Ranges
 
diff --git a/doc/tutorial/basics/scopes.md b/doc/tutorial/basics/scopes.md
index 9945d08..f31bed7 100644
--- a/doc/tutorial/basics/scopes.md
+++ b/doc/tutorial/basics/scopes.md
@@ -8,7 +8,7 @@
 enclosing scope.
 
 If no field matches the reference within the file, it may match a top-level
-field of the same package.
+field defined in any other file of the same package.
 
 If there is still no match, it may match a predefined value.
 
diff --git a/doc/tutorial/basics/templates.md b/doc/tutorial/basics/templates.md
new file mode 100644
index 0000000..d0d25ec
--- /dev/null
+++ b/doc/tutorial/basics/templates.md
@@ -0,0 +1,44 @@
+[TOC](Readme.md) [Prev](lists.md) [Next](instances.md)
+
+_Types ~~and~~ are Values_
+
+# Templates
+
+One of CUE's most powerful features is templates.
+A template defines a value to be unified which each field of a struct.
+
+The template's identifier (in angular brackets) is bound to name of each
+of its sibling fields and is visible within the template value
+that is unified with each of the siblings.
+
+```
+// The following struct is unified with all elements in job.
+// The name of each element is bound to Name and visible in the struct.
+job <Name>: {
+    name:     Name
+    replicas: 1 | uint
+    command:  string
+}
+
+job list command: "ls"
+
+job nginx: {
+    command:  "nginx"
+    replicas: 2
+}
+```
+
+```
+job: {
+    list: {
+        name:     "list"
+        replicas: 1
+        command:  "ls"
+    }
+    nginx: {
+        name:     "nginx"
+        replicas: 2
+        command:  "nginx"
+    }
+}
+```
\ No newline at end of file
diff --git a/doc/tutorial/basics/types.md b/doc/tutorial/basics/types.md
index 5e64faa..e0f80da 100644
--- a/doc/tutorial/basics/types.md
+++ b/doc/tutorial/basics/types.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](bottom.md) [Next](unification.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Basic Types
 
@@ -14,6 +14,7 @@
 int
 float
 ```
+in addition to the error type mentioned in the previous section.
 
 CUE does not distinguish between types and values.
 A field value can be a type (using one of the above names), a concrete value,
diff --git a/doc/tutorial/basics/unification.md b/doc/tutorial/basics/unification.md
index 0d11bbf..bbca5ef 100644
--- a/doc/tutorial/basics/unification.md
+++ b/doc/tutorial/basics/unification.md
@@ -1,6 +1,6 @@
 [TOC](Readme.md) [Prev](types.md) [Next](disjunctions.md)
 
-_Types and Values_
+_Types ~~and~~ are Values_
 
 # Order is Irrelevant