Math: pyhasse.chain
Chain background and Demo
X'(chainj)right } {left X' (chaini) bigcup X'(chainj)right }}
Chain: A subset , with:
 Based on the Hasse diagram a start vertex "start" and a sink vertex "sink" is to be selected.
 Note: start < sink, i.e. the chain module is searching for paths upwards.
 Furthermore a selection is to be done, how many vertices should be in a chain:
The corresponding variable is called maxch.

If “start” and "sink" and "maxch" are appropriately selected chains are identified.
The result is a matrix where chain i is compared with chain j and its similarity due to the TanimotoIndex is calculated:
 The matrix T is also displayed as bar diagram.
 Chains which are of interest can be selected and objects belonging to the selected chain are displayed.