diff --git a/tconfpy.3 b/tconfpy.3
index 98b03ec..5f090ef 100644
--- a/tconfpy.3
+++ b/tconfpy.3
@@ -1777,10 +1777,85 @@
 good idea to put comments throughout such conditional blocks so it's
 clear what is going on.
 
-.SS Existential Conditionals
+.SS Existential Conditional Directives
 
+There are three Existential Conditionals: \'.ifall\', \'.ifany\', and \'.ifnone\'.
+Each has the same syntax:
 
-.SS Comparison Conditionals
+.nf
+    ExistentialDirective [var] ...
+       included if True
+
+   .else # optional
+       include if False
+   
+    .fi
+.fi
+
+In other words, existential conditionals require 
+.B one or more variable references.
+In each case, the actual content of that variable is ignored.  The test is merely
+checking to see
+.B if a variable by that name exists.
+Nothing else may appear on an existential conditional line, except,
+perhaps, a comment.
+
+The three forms of existential conditional tests implement three different kinds of
+logic:
+
+.nf
+     .ifall  [var1] [var2] ...
+
+      This is a logical "AND" operation.  ALL of the variables, \'var1\', \'var2\' ...
+      must exist for this test to be True.
+
+     .ifany [var1] [var2] ...
+
+      This is a logical "OR" operation.  It is True of  ANY of the variables, 
+      \'var1\', \'var2\' ... exist.
+
+     .ifall  [var1] [var2] ...
+
+      This is a logical "NOR" operation.  It is True only if NONE of the variables,
+      \'var1\', \'var2\' ... exist.
+.fi
+
+Here is an example:
+
+.nf
+    F00 = 1
+    BAR = 2
+      z = 0
+
+    .ifall [FOO] [BAR]
+        x = 1
+    .endif
+
+    .ifany [FOO] [foo] [fOo]
+        y = 2
+    .endif
+
+     .ifnone [BAR] [bar] [Bar] [SOmething]
+        z=3
+     .endif
+.fi
+
+When \*(TC finishes processing this, x=1, y=2, and z=0.
+
+You can also use references to environment variables in an existential
+conditional test:
+
+.nf
+    .ifany [$MYPROGOPTIONS]
+       options = [$MYPROGOPTIONS]
+
+    .else
+       options = -b20 -c23 -z -r
+
+    .endif
+.fi
+
+.SS Comparison Conditional Directives
            
 
 .SS The  \'.literal\. Directive