ADDED   docs/manual/bisecting.dot
Index: docs/manual/bisecting.dot
==================================================================
--- /dev/null
+++ docs/manual/bisecting.dot
@@ -0,0 +1,31 @@
+//  Copyright 2021, Matthew Welland.
+// 
+// This file is part of Megatest.
+// 
+//     Megatest is free software: you can redistribute it and/or modify
+//     it under the terms of the GNU General Public License as published by
+//     the Free Software Foundation, either version 3 of the License, or
+//     (at your option) any later version.
+// 
+//     Megatest is distributed in the hope that it will be useful,
+//     but WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//     GNU General Public License for more details.
+// 
+//     You should have received a copy of the GNU General Public License
+//     along with Megatest.  If not, see <http://www.gnu.org/licenses/>.
+//
+digraph G {
+    rankdir=LR
+    subgraph cluster_1 {
+        node [style=filled,shape=box];
+
+	B [label="B\nProblem is here"];
+	E [label="E\nProblem manifests here"];
+	A -> B;
+	B -> C;
+	C -> D;
+	D -> E;
+    }
+
+}