(motive : Lean.Compiler.LCNF.Arg Lean.Compiler.LCNF.Purity.pure → Sort u_1) →
  (arg : Lean.Compiler.LCNF.Arg Lean.Compiler.LCNF.Purity.pure) →
    (Unit → motive Lean.Compiler.LCNF.Arg.erased) →
      ((e : Lean.Expr) → motive (Lean.Compiler.LCNF.Arg.type e ⋯)) →
        ((fvarId : Lean.FVarId) → motive (Lean.Compiler.LCNF.Arg.fvar fvarId)) → motive arg