Contents

    1  Introduction

    2  Call/cc and how to constrain it

    3  Unwind-protect and cobs
        3.1  call/cc-e
        3.2  call/cc-l

    4  Unwind-protect that recognizes only escaping continuations

    5  Unwind-protect that recognizes only last-use continuations

    6  Conclusion

    7  Acknowledgments