document \!

git-svn-id: https://svn.apache.org/repos/asf/ant/antlibs/props/trunk@916797 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/org/apache/ant/props/ConditionEvaluator.java b/src/main/org/apache/ant/props/ConditionEvaluator.java
index 17f7305..6cb6020 100644
--- a/src/main/org/apache/ant/props/ConditionEvaluator.java
+++ b/src/main/org/apache/ant/props/ConditionEvaluator.java
@@ -33,8 +33,8 @@
  * instance matching the condition's outcome.
  *
  * <p>Default syntax is
- * <code><em>condition</em>(<em>attribute</em>=<em>value</em>)</code>,
- * for example <code>os(family=unix)</code>.
+ * <code>[!]<em>condition</em>(<em>attribute</em>=<em>value</em>)</code>,
+ * for example <code>os(family=unix)</code> or <code>!os(family=unix)</code>.
  */
 public class ConditionEvaluator extends RegexBasedEvaluator {
     private static final Pattern COMMA = Pattern.compile(",");