Subclass of:

• sdh:C44 Physical Thing Quality

Scope note:

This class comprises compositions of instances of crm:E18 Physical Thing out of their component elements and is therefore equivalent to the crm:P46 is composed of property but adds a time-indexed dimension to the composition relation, expressing the presence of parts only during a portion of the lifespan of a physical thing. The crm:P46 property is therefore a shortcut of this class and assumes implicitly that a part is present during the whole life of a physical thing.

Parthood : https://en.wiktionary.org/wiki/parthood ; https://plato.stanford.edu/entries/mereology/

This class can be specifically useful for dealing with the belonging of objects to a crm:E78 Collection (the composed, main physical thing) during a particular time-span.

This class is modeled as a subclass of sdh;C1 Entity Quality and therefore instances of the crm:E5 Event class can initiate —crm:P8 effects quality (result from)— or end —crm:P9 ends (is ended by)— a different composition of a physical thing. In the case of instances of crm:E24 Physical Man-Made Thing, instances of crm:E79 Part Addition and crm:E80 Part Removal can be produced.

Component elements, since they are themselves instances of crm:E18 Physical Thing, may be further analysed into sub-components, thereby creating a hierarchy of part decomposition, related to time.

Examples:

The composition of the British Royal Train from 1842 to 1850.

The composition of the Louvre's collection from 1951 to 2018.

In First Order Logic:

• C22(x) ⇒ C44(x)

Outgoing properties:

• sdh:P27 belongs to (has component) (0,n:1,1) → crm:E18 Physical Thing
• sdh:P28 has part (is part of) (0,n:1,1) → crm:E18 Physical Thing