EMMO

• 'EMMO' is the disjoint union of 'Item' and 'Collection' (covering axiom).

The union implies that 'EMMO' individuals can only be 'Item' individuals (standing for self-connected world objects) or 'Collection' individuals (standing for a collection of disconnected items). Disjointness means that a 'Collection' individual cannot be an 'Item' individual and viceversa, representing the fact that a world object cannot be self-connected and non-self connected at the same time. [en]

• Mereotopology is the logical framework used by the EMMO ontologist to characterize the universe and to provide the definitions to connect world objects to the EMMO concepts.

For the EMMO ontologist the whole universe is the most comprehensive object. World objects are then sub-parts of the universe. The fundamental distinction between world objects, upon which the EMMO is based, is self-connectedness: a world object can be self-connected xor not self-connected. Parthood relations do not change dimensionality of the world object: every part of a world object is another world object and always retains a 4D dimensionality character. The smallest part of a world object (i.e. a part that has no proper parts) is called a 'Quantum' individual. Quantum individuals are the fundamental causal constituents of the universe. They are no-dimensional, and their aggregation makes 4D objects emerge from their causal structure. It follows that, for the EMMO, world objects of dimensionality lower than 4D (e.g. surfaces, lines) do not exist. In the EMMO there are no relations such as occupiesSpace, since objects are themselves the 4D regions.