Domain Theory

A domain theory provides a logical language for the application domain:

• Time: time is abstract, but has several concrete representations (ephemeris time, UTC, spacecraft clock time)
• Points, rays, planes
• Photon travel
• Events (space-time points)
• Celestial bodies, e.g. Saturn
• Axioms that relate abstract and concrete terms.

∀ tc (= (absctt UTC tc)
         (absctt Ephemeris (UTC2Ephemeris tc)))

∀ tc (= (absctt Ephemeris tc)
         (absctt UTC (Ephemeris2UTC tc)))

absctt abstracts from a time system and time coordinate to an abstract time. These axioms specify what the conversion functions such as Ephemeris2UTC do.

Representation conversions are combinatorially explosive because they can loop.