Extra 3 / 12 · Uncertainty
Partial coordinates
You are locating a point one third of the way between two controls. One control’s vertical coordinate is still unknown. The horizontal calculation can nevertheless be complete.
Selected result
What remains connected
What is checked, and where this example stops
Selected interpolation returns x = 0 with an open y, then an exact 7/3 when the premise is complete. Separate requests test refused and permitted extrapolation.
The steps compare separately authored requests. These are chosen local reads; there is no automatic search for missing coordinates or permission to extrapolate.