Research proof index

Given a list i :: l the left-most minimal position a of i :: l wrt r as an element of Fin (insertionSortDropMinPos r i l).length.succ. -/ def insertionSortMinPosFin {α : Type} (r : α → α → Prop) [DecidableRel r] (i : α) (l : List α) : Fin (insertionSortDropMinPos r i l).length.succ := ⟨insertionSortMinPos r i l, insertionSortMin_lt_length_succ r...