www.entitymodelling.org - entity modelling introduced from first principles - relational database design theory and practice - dependent type theory
Khipus (or quipus) were structured systems of knots used by the Inca people to communicate and record numerical records. A relatively small number of khipus survived the Spanish conquest of South America and by and large are now held in museums. Structural details of each of these khipus have been described in a database by the Khipu Database Project1. I have drawn the entity model shown here to describe this structure. You can think of this model as a modern meta description of an ancient database system.