{motive : Lean.Language.Lean.LeanProcessingContext → Sort u} →
  (t : Lean.Language.Lean.LeanProcessingContext) →
    ((toProcessingContext : Lean.Language.ProcessingContext) →
        (firstDiffPos? : Option String.Pos.Raw) →
          motive { toProcessingContext := toProcessingContext, firstDiffPos? := firstDiffPos? }) →
      motive t