Key equation (strong triangle inequality)
d(x, z) ≤ max{ d(x, y), d(y, z) }
Ultrametric property: error cannot leak outside the infected subtree
Key insight — verify it yourself
In an Archimedean (Euclidean) space, an error at node v could potentially affect any other node — sibling, parent, or distant cousin — because triangle paths can connect everything.
In an ultrametric space (Bruhat–Tits tree), the strong triangle inequality locks the error inside the subtree of v.
Click nodes at different depths: the shallower the error, the larger the affected subtree. A leaf error affects only itself (perfect confinement).
This property makes p-adic QEC codes exponentially more efficient at suppressing cascading errors.
Source: QWAV A1 · DOI 10.5281/zenodo.20134944