Is there a straightforward way to prove A ==> B ==> C equal to (A & B )==> C

[ChuyueSun]

I am trying to prove this lemma:

twostate lemma helper(arr: array<int>, k: int)
  requires forall i :: 0 <= i < arr.Length ==> old(arr[i]) <= k ==> arr[i] == old(arr[i])
  ensures  forall i: int :: 0 <= i < arr.Length && old(arr[i]) <= k ==> arr[i] == old(arr[i])
{
}

Seems like I am missing a trigger.