Jetisu

Jetisu is a toolset for modelling with intensionally defined relations.

• a "relation" is a table with columns and rows,
• "intensionally defined" means the the table is defined by computable rules rather than by a list of rows.

Modelling Rules As Code

The examples are chosen to illustrate the benefits (and/or challenges) of using intensionally defined relations to model rules as code.

• ACT Conveyance Duty
• Australian GST
• Birthday Money
• Range

Edit and re-run the example notebooks

You can docker run the example Jupyter notebooks for yourself.

docker run XXXXXXXXXXX

Unpacking "intensionally defined"

Every table has an intension, which is its intended meaning and its extension which is its list of rows. But not all tables are defined in the same way!

How defined	Intension (a test that is true if a row is a member of the table)	Extension (list of rows)
Extensionally defined	Natural Language	Listed out in a table
Intensionally defined	Computable Constraints and Rules	Generated or recognised on demand

Our databases and CRMs are full of extensionally defined tables, here are a few:

Intension (intended meaning)	Extension (list of rows)
Our Customers	1 row in a table for each customer
Our Orders	1 row in a table for each order