Companion explorer
The incidence mirror.
Reorder the facet columns by the self-duality Φ. The complete vertex–facet incidence matrix becomes visibly symmetric.
Columns are ordered by Φ
M is symmetric.
Column j is the facet dual to row vertex j. Selecting an entry also marks its reflection across the diagonal.
M1,11=M1,11
C_{0,∅} ∈ O₀,∅
incidence diagonal reflected entry
| v \ Φ(w) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|