**TODO** list:
- functional integrity constraints (CIF)
- - inter-relations constraints (or, and, xor...)
+ - inter-relations constraints (or, and, xor, inclusion)
- inheritance with the right symbol (triangle)
- - put online somewhere (user enter graph description and get SVG + SQL)
-*Implementation note:* temporary dependency to [underscore](http://underscorejs.org/); good library but used so far only for its shuffle() method.
+*Implementation note:* temporary dependency to [underscore](http://underscorejs.org/); used only for its shuffle() method.