sysdbql(7): Document IS [NOT] TRUE / FALSE.

diff --git a/doc/sysdbql.7.txt b/doc/sysdbql.7.txt
index 9a16e23a4593f58f7ca582728e4828b6d68205aa..de7c7c472b754a442ee264870d83788a3eeee103 100644 (file)
--- a/doc/sysdbql.7.txt
+++ b/doc/sysdbql.7.txt
@@ -129,6 +129,13 @@ Boolean expressions may use the following operators:
        expression evaluates to NULL if the queried object does not exist (e.g.,
        when accessing an attribute value).
 
+'<expression>' *IS TRUE*::
+'<expression>' *IS NOT TRUE*::
+'<expression>' *IS FALSE*::
+'<expression>' *IS NOT FALSE*::
+       Check whether an expression evaluates to a boolean *true* or *false* value
+       (or not).
+
 '<expression>' *IN* '<expression>'::
 '<expression>' *NOT IN* '<expression>'::
        Checks whether the value of the first expression is included in the value