4 files changed, 27 insertions, 21 deletions
diff --git a/doc/manual/expressions/builtins.xml b/doc/manual/expressions/builtins.xml
index eae5f5a029bf..6ac802343236 100644
--- a/doc/manual/expressions/builtins.xml
+++ b/doc/manual/expressions/builtins.xml
@@ -142,7 +142,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
     evaluates to the Nix platform identifier for the Nix installation
     on which the expression is being evaluated, such as
     <literal>"i686-linux"</literal> or
-    <literal>"powerpc-darwin"</literal>.</para></listitem>
+    <literal>"x86_64-darwin"</literal>.</para></listitem>
 
   </varlistentry>
 
@@ -853,7 +853,14 @@ builtins.sort builtins.lessThan [ 483 249 526 147 42 77 ]
     len</replaceable> lies beyond the end of the string, only the
     substring up to the end of the string is returned.
     <replaceable>start</replaceable> must be
-    non-negative.</para></listitem>
+    non-negative. For example,
+
+<programlisting>
+builtins.substring 0 3 "nixos"
+</programlisting>
+
+   evaluates to <literal>"nix"</literal>.
+   </para></listitem>
 
   </varlistentry>
 
diff --git a/doc/manual/expressions/derivations.xml b/doc/manual/expressions/derivations.xml
index f2a73dccfe18..5efe2213e370 100644
--- a/doc/manual/expressions/derivations.xml
+++ b/doc/manual/expressions/derivations.xml
@@ -16,7 +16,7 @@ of which specify the inputs of the build.</para>
   <listitem xml:id="attr-system"><para>There must be an attribute named
   <varname>system</varname> whose value must be a string specifying a
   Nix platform identifier, such as <literal>"i686-linux"</literal> or
-  <literal>"powerpc-darwin"</literal><footnote><para>To figure out
+  <literal>"x86_64-darwin"</literal><footnote><para>To figure out
   your platform identifier, look at the line <quote>Checking for the
   canonical Nix system name</quote> in the output of Nix's
   <filename>configure</filename> script.</para></footnote> The build
diff --git a/doc/manual/expressions/language-constructs.xml b/doc/manual/expressions/language-constructs.xml
index 7535e64ea9a5..fe69dba837a1 100644
--- a/doc/manual/expressions/language-constructs.xml
+++ b/doc/manual/expressions/language-constructs.xml
@@ -202,24 +202,6 @@ in concat { x = "foo"; y = "bar"; }</programlisting>
 
 </para>
 
-<para>A set that has a <literal>__functor</literal> attribute whose value
-is callable (i.e. is itself a function or a set with a
-<literal>__functor</literal> attribute whose value is callable) can be
-applied as if it were a function, with the set itself passed in first
-, e.g.,
-
-<programlisting>
-let add = { __functor = self: x: x + self.x; };
-    inc = add // { x = 1; };
-in inc 1
-</programlisting>
-
-evaluates to <literal>2</literal>. This can be used to attach metadata to a
-function without the caller needing to treat it specially, or to implement
-a form of object-oriented programming, for example.
-
-</para>
-
 </simplesect>
 
 
diff --git a/doc/manual/expressions/language-values.xml b/doc/manual/expressions/language-values.xml
index f1174ecb5d8d..b90baac5054c 100644
--- a/doc/manual/expressions/language-values.xml
+++ b/doc/manual/expressions/language-values.xml
@@ -276,6 +276,23 @@ added to the set:
 This will evaluate to <literal>{}</literal> if <literal>foo</literal>
 evaluates to <literal>false</literal>.</para>
 
+<para>A set that has a <literal>__functor</literal> attribute whose value
+is callable (i.e. is itself a function or a set with a
+<literal>__functor</literal> attribute whose value is callable) can be
+applied as if it were a function, with the set itself passed in first
+, e.g.,
+
+<programlisting>
+let add = { __functor = self: x: x + self.x; };
+    inc = add // { x = 1; };
+in inc 1
+</programlisting>
+
+evaluates to <literal>2</literal>. This can be used to attach metadata to a
+function without the caller needing to treat it specially, or to implement
+a form of object-oriented programming, for example.
+
+</para>
 
 </simplesect>