(motive : Option Mathlib.Tactic.UnfoldBoundary.UnfoldBoundaryExt → Sort u_1) →
  (x : Option Mathlib.Tactic.UnfoldBoundary.UnfoldBoundaryExt) →
    ((unfoldBoundaries : Mathlib.Tactic.UnfoldBoundary.UnfoldBoundaryExt) → motive (some unfoldBoundaries)) →
      ((x : Option Mathlib.Tactic.UnfoldBoundary.UnfoldBoundaryExt) → motive x) → motive x