pub fn triangle_lookup_perms(leader_idx: u8) -> Vec<LookupPerm>Expand description
Promoter helper: triangle canonical permutation table.
Returns lookup_perms (the 2 non-leader slot entries) for the
given leader_idx ∈ [0, 3). The promoter combines this with its
own knowledge of the rule head to produce
kernel_output_cols.
Canonical semantics:
- 0 (e_xy default) — slots
[e_yz, e_xz], no col-swaps. - 1 (e_yz) — slots
[e_xz↔, e_xy↔], both col-swapped. - 2 (e_xz) — slots
[e_yz↔, e_xy], e_yz col-swapped only.