(motive : (pu : Lean.Compiler.LCNF.Purity) → Lean.Compiler.LCNF.FunDecl pu → Sort u_1) →
  (pu : Lean.Compiler.LCNF.Purity) →
    (funDecl : Lean.Compiler.LCNF.FunDecl pu) →
      ((funDecl : Lean.Compiler.LCNF.FunDecl Lean.Compiler.LCNF.Purity.pure) →
          motive Lean.Compiler.LCNF.Purity.pure funDecl) →
        ((funDecl : Lean.Compiler.LCNF.FunDecl Lean.Compiler.LCNF.Purity.impure) →
            motive Lean.Compiler.LCNF.Purity.impure funDecl) →
          motive pu funDecl