Ontology

The Pushlogic approach defines its own ontology. This covers device structure and also domains of participation.

Glossary

Pebble.

A pebble is a basic entity that can register its existance in a domain, broadcast events and be controlled over the network. A pebble does not interact directly with any other pebble.

Bundle.

A bundle of Pushlogic rules consists of software, temporal logic assertions and meta information. It may be interpreted by a Pushlogic exection platform or be natively compiled. It is the only class of entity that provides communication between Pebbles.

Canned Bundle.

A canned bundled is stored in a file on a server or in ROM, ready for re-hydration. It may contain formal variables that are replaced in macro-expansion style to actual variable (field/tuple) references.

Soft Pebble.

A soft pebble is one that can run on any networked execution platform. It has no specialised or associated hardware.

Device.

A device contains Pebbles and Bundles, execution resources and other system services that are neither Pebbles or Bundles.

Service.

A service is the same as a device. However, the term is used for software-only devices. These can generally be dynamically instantiated whereas hardware devices are instantiated by a user introducing one into the domain.

Domain of Participation.

A DoP is any space in which a quantifier ranges. Typically this covers a physical or logical space. Most-trivially, it is the local UDP broadcast subnet. An example use of a DoP is a rule which says 'all lights must be off when the master switch is off': in this example, the word 'all' is interpreted with respect to the current DoP. Devices and Pebbles can participate in several domains at once (Atif is working on this).