1 files changed, 29 insertions, 30 deletions

diff --git a/source/arduino/booleanvariables.rst b/source/arduino/booleanvariables.rst
index 3bbe72a..772db0f 100644
--- a/source/arduino/booleanvariables.rst
+++ b/source/arduino/booleanvariables.rst
@@ -1,53 +1,52 @@
+.. highlight:: cpp
+
 .. _arduino-booleanvariables:
 
-boolean
-=======
+Booleans
+========
 
-A **boolean** holds one of two values,
-`true <http://arduino.cc/en/Reference/Constants>`_ or
-`false <http://arduino.cc/en/Reference/Constants>`_. (Each boolean
-variable occupies one byte of memory.)
+A **boolean** holds one of two values, :ref:`true
+<arduino-constants-true>` or :ref:`false <arduino-constants-false>`.
+On a Maple, each boolean variable occupies one byte of memory, and has
+type ``bool``.
 
+.. warning::
 
+   On an Arduino, the type ``boolean`` is also provided.  While the
+   Maple also has this type for compatibility, **its use is strongly
+   discouraged**.  The ``bool`` type is a standard part of C++, while
+   ``boolean`` is a non-standard extension that serves no purpose.
 
 Example
 -------
 
 ::
 
-    int LEDpin = 5;       // LED on pin 5
-    int switchPin = 13;   // momentary switch on 13, other side connected to ground
-    
-    boolean running = false;
-    
-    void setup()
-    {
-      pinMode(LEDpin, OUTPUT);
+    int ledPin = 13;      // LED on pin 13
+    int switchPin = 12;   // momentary switch on 12, other side connected to ground
+
+    // running is a boolean variable:
+    bool running = false;
+
+    void setup() {
+      pinMode(ledPin, OUTPUT);
       pinMode(switchPin, INPUT);
       digitalWrite(switchPin, HIGH);      // turn on pullup resistor
     }
-    
-    void loop()
-    {
-      if (digitalRead(switchPin) == LOW)
-      {  // switch is pressed - pullup keeps pin high normally
+
+    void loop() {
+      if (digitalRead(switchPin) == LOW) {
+        // switch is pressed - pullup keeps pin high normally
         delay(100);                        // delay to debounce switch
         running = !running;                // toggle running variable
-        digitalWrite(LEDpin, running)      // indicate via LED
+        digitalWrite(ledPin, running)      // indicate via LED
       }
     }
-    
-    
-    
-
-
 
 See also
 --------
 
 
--  `constants <http://arduino.cc/en/Reference/Constants>`_
--  `boolean operators <http://arduino.cc/en/Reference/Boolean>`_
--  `Variable Declaration <http://arduino.cc/en/Reference/VariableDeclaration>`_
-
-
+-  :ref:`Boolean constants <arduino-constants-bool>`
+-  :ref:`Boolean operators <arduino-boolean>`
+-  :ref:`Variables <arduino-variables>`