fluent-definition-time-dependent-predicate
IN premise — summaries/2026/08/24/wiki-Frame_problem-chunk-1.md
Created 2026-08-25T02:58:48+00:00
A fluent is a time-dependent predicate (e.g., open(t), on(t)) representing a condition that can change over time, as opposed to a static proposition.
Summary
Some facts in the world are fixed (like a shape's geometry), but others shift depending on when you look at them, such as whether a door is open or a block is sitting on another. The system tracks these changing conditions with a timestamp, so it can reason about when a state started and ended rather than treating it as a permanent, timeless truth.