Required inputs
Body and ephemeris
Time interval
Frame and boundary longitude
Search step and root tolerance
Ordered execution
Work the protocol
- 1
Sample the entire interval.
- 2
Unwrap longitude around the target.
- 3
Bracket every sign change.
- 4
Refine each bracket to tolerance.
- 5
Label direct or retrograde crossing and retain all roots.
Outputs
- Ordered ingress roots
- Crossing directions
- Search receipt
Done only when
- Every bracket is refined.
- Repeated crossings remain distinct.
- Search parameters are digest-bound.
Fail closed
Refusal conditions
- Only the first crossing is returned.
- Frame or ayanāṁśa is implicit.
- The search interval is chosen after observing an event.
Recomputable fixture
Calculation receipt
The output and digest are derived from the displayed inputs. The fixture demonstrates the operation, not an astrological prediction.
operation linear-ingress-root
input.startSeconds 0
input.endSeconds 3600
input.startDegrees 29.8
input.endDegrees 30.2
input.targetDegrees 30
output.rootSeconds 1800
output.method linear-bracket-fixture
sha256:8731ccebd91155a81e956b9b61eec02d7b26065832741bcb5025e94983c2bf73
Uncertainty: The fixture root is exact under linear interpolation; production uncertainty is bounded by ephemeris, sampling, and root tolerances.