(motive : Option (Lean.Syntax.TSepArray `ident ",") → Sort u_1) →
  (ids? : Option (Lean.Syntax.TSepArray `ident ",")) →
    ((ids : Lean.Syntax.TSepArray `ident ",") → motive (some ids)) →
      ((x : Option (Lean.Syntax.TSepArray `ident ",")) → motive x) → motive ids?