{motive : Lean.ErrorExplanation → Sort u} →
  ((doc : String) →
      (metadata : Lean.ErrorExplanation.Metadata) →
        (declLoc? : Option Lean.DeclarationLocation) →
          motive { doc := doc, metadata := metadata, declLoc? := declLoc? }) →
    (t : Lean.ErrorExplanation) → motive t