Subsumption test

A subsumption test is the act of testing X to see if is subsumed by Y. The question can also be reversed by asking "Does Y subsume X?".

if X is subsumed by Y it means that all objects of type X are also objects of type Y. Class X is thus either a subclass of class Y, or is equivalent to class Y

Subsumption testing is the mainstay of health record query. It is the major differentiator of health care records from conventional database records that have simple codes or data types as values.

To take an example, when examining an entry in a health record that purports to be a diganosis, one could ask "is this diagnosis a communicable disease caused by a virus?".

Conversely, one might be interested in finding all the entries in a population of health records that are "communicable diseases caused by a virus", or even a question against an ontology such as "Get me a list of all communicable diseases caused by a virus".

The challenge to overcome is that in most cases, the relevant concepts that are X are not within a hierarchy of codes as specified by Y. There is no classification of diseases organised by whether they are communicable AND caused by viruses. Instead it is necessary to use a process called  [https://en.wikipedia.org/wiki/Inference inference]