Improving expand function documentation

wiki/content/query-language/index.md

@@ -1796,19 +1796,31 @@ Query Example: Actors from Tim Burton movies and how many roles they have played
 }
 {{< /runnable >}}
 
-
-
 ## Expand Predicates
 
 The `expand()` function can be used to expand the predicates out of a node. To
- use `expand()`, the [type system]({{< relref "#type-system" >}}) is required.
+use `expand()`, the [type system]({{< relref "#type-system" >}}) is required.
 Refer to the section on the type system to check how to set the types
 nodes. The rest of this section assumes familiarity with that section.
 
-There are four ways to use the `expand` function.
+There are two ways to use the `expand` function.
+
+* Types can be passed to `expand()` to expand all the predicates in the type.
+
+Query example: List the movies from the Harry Potter series:
+
+{{< runnable >}}
+{
+  all(func: eq(name@en, "Harry Potter")) @filter(type(Series)) {
+    name@en
+    expand(Series) {
+      name@en
+      expand(Film)
+    }
+  }
+}
+{{< /runnable >}}
 
-* Predicates can be stored in a variable and passed to `expand()` to expand all
-  the predicates in the variable.
 * If `_all_` is passed as an argument to `expand()`, the predicates to be
 expanded will be the union of fields in the types assigned to a given node.
 
@@ -1844,9 +1856,11 @@ owner
 veterinarian
 ```
 
+{{% notice "note" %}}
 For `string` predicates, `expand` only returns values not tagged with a language
 (see [language preference]({{< relref "#language-support" >}})).  So it's often 
 required to add `name@fr` or `name@.` as well to an expand query.
+{{% /notice  %}}
 
 ### Filtering during expand.