{P : Sort u} →
  {toWidgetInstance : Lean.Widget.WidgetInstance} →
    {stx : Lean.Syntax} →
      {toWidgetInstance' : Lean.Widget.WidgetInstance} →
        {stx' : Lean.Syntax} →
          { toWidgetInstance := toWidgetInstance, stx := stx } =
              { toWidgetInstance := toWidgetInstance', stx := stx' } →
            (toWidgetInstance = toWidgetInstance' → stx = stx' → P) → P