value > 0, torsion 0 — CALORIE
value > 0, torsion ≠ 0 — CURE
value < 0, torsion 0 — inverted
value < 0, torsion ≠ 0 — inverted cure
value = 0 — SYNC
black is absence, never a value
No substrate colour is black. That is what keeps the field readable: if a
zero-valued cell were black, an assertion of zero and the absence of substrate would be
indistinguishable, and no amount of determinism could recover the difference.