Required inputs
Body
Apparent longitude function
Search interval
Derivative step
Root tolerance
Ordered execution
Work the protocol
- 1
Evaluate signed motion on a fixed grid.
- 2
Bracket every sign change.
- 3
Refine the zero of motion.
- 4
Classify direct-to-retrograde or reverse.
- 5
Retain near-zero uncertainty around the root.
Outputs
- Station instant set
- Direction changes
- Motion receipt
Done only when
- Each root has an opposing-sign bracket.
- Direction is explicit.
- Tolerance and ephemeris are recorded.
Fail closed
Refusal conditions
- A rounded zero is accepted without a sign change.
- One station is assumed per interval.
- Geocentric and topocentric motion are mixed.
Recomputable fixture
Calculation receipt
The output and digest are derived from the displayed inputs. The fixture demonstrates the operation, not an astrological prediction.
operation station-bracket
input.motionBeforeDegreesPerDay 0.1
input.motionAfterDegreesPerDay -0.1
output.bracketed true
output.direction direct-to-retrograde
sha256:0c7adcaf8603595721dd1a333bc6086286479faabe0c11dafff5667291d51528
Uncertainty: The fixture proves a bracket and direction only; it does not estimate the station instant inside the bracket.