(motive : Option (Lean.Compiler.LCNF.Arg Lean.Compiler.LCNF.Purity.impure) → Sort u_1) →
  (x : Option (Lean.Compiler.LCNF.Arg Lean.Compiler.LCNF.Purity.impure)) →
    ((fvarId : Lean.FVarId) → motive (some (Lean.Compiler.LCNF.Arg.fvar fvarId))) →
      (Unit → motive (some Lean.Compiler.LCNF.Arg.erased)) → (Unit → motive none) → motive x