anchor.diff:  # Install Jupyter Notebook first
   RUN pip3 install --upgrade pip
   RUN pip3 install jupyter
  +## RUN pip3 install jupyterlab # try jupyterlab
   # Install Jupyter Hub second
   RUN python3 -m pip install jupyterhub
   RUN npm install -g configurable-http-proxy
   RUN python3 -m pip install notebook  # needed if running the notebook servers locally
  +#RUN jupyter labextension install @jupyterlab/hub-extension  # try jupyterlab
   
   # check??
   #jupyterhub -h
  
positive.code: #Install Lisp: sbcl
  RUN wget http://prdownloads.sourceforge.net/sbcl/sbcl-1.2.9-x86-64-linux-binary.tar.bz2 -O /cre/sbcl.tar.bz2 && \
      mkdir /cre/sbcl && \
      tar jxvf /tmp/sbcl.tar.bz2 --strip-components=1 -C /cre/sbcl/ && \
      cd /cre/sbcl && \
      sh ./install.sh && \
      cd /cre && \
  
negative.code: # https://github.com/fredokun/cl-jupyter/blob/master/about-cl-jupyter.ipynb
  #
  # https://irkernel.github.io/
  #
  # https://jupyterlab.readthedocs.io/en/stable/user/jupyterhub.html
  # https://nbconvert.readthedocs.io/en/latest/install.html#installing-nbconvert
  
  # Jupyter Hub Dockerfile 
  #
  