Calibrated contour rotation
This later experiment supplies an X/Y basis, a metric and radial landmarks, then checks how an attached plate turns. It does not construct those landmarks. Start with the circle construction to see the earlier stages. Each example below starts from the same original plate.
Look at the actual syntax
Selected lines from the authored fixture. The full fixture connects the basis, metric, shared markers and points. A caller selects a reader and binds its request; these declarations describe the inputs.
let $contour = crystal(orthogonal($origin));
let $centre_representation = $origin -> $centre;
let $rims = frame($m0 -> ($centre -> $p0), $m1 -> ($centre -> $p1),
$m2 -> ($centre -> $p2), $m3 -> ($centre -> $p3));
let $cycle = frame($m0 -> $m1, $m1 -> $m2, $m2 -> $m3, $m3 -> $m0);
let $surface = group($centre_representation, $contour, $metric, $rims, $cycle);
let $walk = group($surface, $m0, span($steps, 0, 1));
root group(?traversal, $points);
A recorded replay checked against the Gojo readers. The browser draws the checked coordinates; it does not execute the kernel. This experiment selects an exact planar distance rule and discrete landmarks. Smooth motion, physical torque and uncertain radial geometry remain later work. No angle parameter defines these turns.