Added to sandbox doc

db085f50 · Joseph Turian · 9d2c0288 · db085f50
--- a/doc/doc/sandbox.txt
+++ b/doc/doc/sandbox.txt
@@ -99,6 +99,11 @@ How to use the PrintOp

 ** This is also useful in the How to write an Op tutorial. **

+=======================================================
+Modules
+=======================================================
+
+* What is the correct way to tie weights?

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 Mammouth