anchor.diff:  
   # libav-tools for matplotlib anim
   RUN apt-get update && \
  -	apt-get install -y --no-install-recommends libav-tools && \
  -	apt-get install -y git \
  -					   gcc \
  -					   g++ \
  -					   gfortran \
  -					   libatlas-dev \
  -					   libatlas-base-dev \
  -					   libfreetype6-dev && \
  -	apt-get clean && \
  -	rm -rf /var/lib/apt/lists/*
  +  apt-get install -y --no-install-recommends libav-tools && \
  +  apt-get install -y git \
  +             gcc \
  +             g++ \
  +             gfortran \
  +             libatlas-dev \
  +             libatlas-base-dev \
  +             libfreetype6-dev && \
  +  apt-get clean && \
  +  rm -rf /var/lib/apt/lists/*
   # Official Debian and Ubuntu images automatically run apt-get clean
   
   ### Change locale to en_GB
   # https://github.com/jupyter/docker-stacks/blob/master/minimal-notebook/Dockerfile
   
  -RUN echo "en_GB.UTF-8 UTF-8" > /etc/locale.gen && \ 
  -	locale-gen 
  +RUN echo "en_GB.UTF-8 UTF-8" > /etc/locale.gen && \
  +  locale-gen
   
   ENV LC_ALL en_GB.UTF-8
   ENV LANG en_GB.UTF-8
  
positive.code: 
  RUN apt-get clean && \
      apt-get autoremove && \
  	rm -rf /var/lib/apt/lists/*
  
  ### Copy demonstration notebook and config files to home directory
  COPY Prometheus_demo.ipynb /home/$NB_USER/work/
  
negative.code: 
  RUN cd $NDIR/iv; ./build.sh; ./configure --prefix=`pwd` --with-x --x-includes=/usr/include/ --x-libraries=/usr/lib/ && make && make install
  
  #RUN cd $NDIR/nrn; sh src/nrnmpi/mkdynam.sh; ./build.sh;
  RUN cd $NDIR/nrn; ./build.sh;
  RUN cd $NDIR/nrn; 2to3 -w src/oc/mk_hocusr_h.py; sed -i '1i from __future__ import print_function' src/oc/mk_hocusr_h.py
  RUN cd $NDIR/nrn; sudo sed -i.bak -e "s/print sys.api_version,/from __future__ import print_function; print(sys.api_version)/" configure
  # --with-music=/usr/local
  