| valid-indices(wlar, nx), wlar0 = wlar, nx0 = nx, ¬ dups(nx) ⊦ ⟪ubi_fix_ecs#(n; nx, wlar)⟫ (wlar = wlar0.mapIndices(nx0, λ wle. wle.ec:= n)) |
nx0 = nx, wlar0 = wlar, valid-indices(wlar, nx) ⊦ ⟪ubi_fix_ecs#(n; nx, wlar)⟫ (wlar = wlar0.mapIndices(nx0, λ wle. wle.ec:= n)), dups(nx)