intro arr isLt hLen
case succ
α : Type u_1
inst✝ : Ord α
len i' : Nat
ih :
  ∀ (arr : Array α) (isLt : i' < Array.size arr),
    Array.size arr = len → Array.size (insertSorted arr { val := i', isLt := isLt }) = len
⊢ ∀ (arr : Array α) (isLt : Nat.succ i' < Array.size arr),
    Array.size arr = len → Array.size (insertSorted arr { val := Nat.succ i', isLt := isLt }) = len
case succ
α : Type u_1
inst✝ : Ord α
len i' : Nat
ih :
  ∀ (arr : Array α) (isLt : i' < Array.size arr),
    Array.size arr = len → Array.size (insertSorted arr { val := i', isLt := isLt }) = len
arr : Array α
isLt : Nat.succ i' < Array.size arr
hLen : Array.size arr = len
⊢ Array.size (insertSorted arr { val := Nat.succ i', isLt := isLt }) = len