anchor.diff:      julia \
       libnettle4 && apt-get clean
   
  +USER jovyan
  +
   # Install Python 3 packages
   RUN conda install --yes \
       'ipywidgets=4.0*' \
  
positive.code:     'r-rcurl=1.95*' \
      'r-randomforest=4.6*' && conda clean -yt
  
  # IJulia and Julia packages
  RUN julia -e 'Pkg.add("IJulia")'
  RUN julia -e 'Pkg.add("Gadfly")' && julia -e 'Pkg.add("RDatasets")'
  
negative.code:     'bokeh=0.9*' \
      && conda clean -yt
  
  # Install Python 2 packages
  RUN conda create -p $CONDA_DIR/envs/python2 python=2.7 \
      'ipython=4.0*' \
      'ipywidgets=4.0*' \
  