| #c mx ≠ 0, #dirtyrows(mx, i) ≤ 1 ⊦ (∀ r. r < #r mx → count(mx[r]r, λ j. j < i) = 0 ∨ count(mx[r]r, λ j. ¬ j < i) = 0) ∨ (∃ r0. count(mx[r0]r, λ j. j < i) ≠ 0 ∧ count(mx[r0]r, λ j. ¬ j < i) ≠ 0 ∧ (∀ r. r ≠ r0 ∧ r < #r mx → count(mx[r]r, λ j. j < i) = 0 ∨ count(mx[r]r, λ j. ¬ j < i) = 0)) |