# Glossary

## Action
## Actor
## Assertion
## Attenuation
## Capability

a.k.a. Cap

Pointer or handle denoting a live, stateful [entity](#entity) running within an
[actor](#actor). The entity accepts [Preserves](#preserves)-format [messages](#message) and/or
[assertions](#assertion). The capability may be [attenuated](#attenuation) to restrict the
messages and assertions that may be delivered to the denoted entity by way of this particular
handle.

## Compositional
## Configuration Scripting Language
## Conversational State
## Dataspace
## Dataspace Pattern
## E
## Embedded References
## Entity
## Event
## Facet
## Initial OID
## Initial Ref
## Macaroon

[*“Macaroons: Cookies with Contextual Caveats for Decentralized Authorization in the
Cloud.”*](https://research.google/pubs/pub41892/), by Arnar Birgisson, Joe Gibbs Politz, Úlfar
Erlingsson, Ankur Taly, Michael Vrable, and Mark Lentczner. In Proc. Network and Distributed
System Security Symposium (NDSS), 2014. [[PDF]](https://research.google/pubs/pub41892.pdf)

## Membrane
## Message
## Network

A network is a group of peers, plus a medium of communication, an addressing model, and an
associated [scope](#scope).

## Object Capability Model
## Observe
## OID
## Preserves
## Record
a Preserves record
## Reference
a.k.a. "Ref", "Entity Reference"
## Relay
## Relay Entity
## S6
## Schema
## Scope

A *scope* maps [refs](#reference) to the [entities](#entity) they denote. Scopes exist in
one-to-one relationship to [networks](#network). Because [message bodies](#message) and
[asserted values](#assertion) contain [embedded references](#embedded-references), each message
and assertion transmitted via some network is also inseparable from its scope.

Most [actors](#actor) will participate in a single scope. However, [relay](#relay) actors
participate in two or more scopes, translating refs back and forth as messages and assertions
traverse the relay.

**Examples.**

 1. A process is a scope for in-memory values: in-memory refs contain direct pointers to
    entities, which cannot be interpreted outside the context of the process's address space.
    The "network" associated with the process's scope is the intra-process graph of object
    references.

 2. A TCP/IP socket (or serial link, or WebSocket, or Unix socket, etc.) is a scope for values
    travelling between two connected processes: [refs on the wire](#wire-symbol) denote
    entities owned by one or the other of the two participants. The "network" for a socket's
    scope is exactly the two connected peers (NB. and is *not* the underlying TCP/IP network,
    HTTP network, or Unix kernel that supports the point-to-point link).

 3. An ethernet segment is a scope for values broadcast among stations: the embedded refs are
    (MAC address, [OID](#oid)) pairs. The network is the set of participating peers.

 4. A running web page is a scope for the JavaScript objects it contains: both local and remote
    entities are represented by JavaScript objects. The "network" is the JavaScript heap.

## Supervision tree
## Supervisor
## Sync Peer Entity
## Synchronization
(`sync` action)
## Syndicated Actor Model

Often abbreviated **SAM**.

Source [entities](#entity) running within an [actor](#actor) publish [assertions](#assertion)
and send [messages](#message) to target entities, possibly in other actors.

Essential idea: state replication is more useful than message-passing. (Message-passing
protocols usually end up simulating it, badly, anyway.)

## System Layer
## System Dataspace
## Transport
## Turn
## Wire Symbol