
Data and Concepts AnalysisData and Concepts Analysis 175
The structure is known as the direct product of the two given lattices.
The nodes belonging to the sub-structure are drawn in black as opposed
to the remaining void nodes drawn in white. We read for instance that
property a, separate compounds 1, 6, 7 and 8, the slash adds the compound
3, while the property b adds the compounds 2, 4 and 5.
Properties a and b correspond to specifi c separation devices. After the
fi rst level separation the secondary properties would be considered.
The commutation situation for the involved lattices is:
DU–UD=0 (9.1)
9.2.2 Graphs Spanning for Comparison
The idea ...