anchor.diff:        && tar xfz bazel-bin/archive.tar.gz --strip-components 4 -C /usr \
   # Install Python3 Binding
         && python3 setup.py bdist_wheel \
  -      && pip3 install ./dist/dreal-*-cp36-none-manylinux1_x86_64.whl \
  +      && pip3 install ./dist/dreal-*-cp38-none-manylinux1_x86_64.whl \
         && bazel clean --expunge \
   # Clean up
         && cd / \
         && rm -rf dreal4 \
         && rm -rf /root/.cache/bazel \
         && rm -rf /var/lib/apt/lists/* \
  -      && apt-get remove -y bazel bison flex g++ wget python-zipstream \
  +      && apt-get remove -y bazel bison flex g++ wget \
         && apt-get autoclean -y \
         && apt-get autoremove -y
  
positive.code: # Install prerequisites.
  ARG DEBIAN_FRONTEND=noninteractive
  RUN apt-get update \
        && yes "Y" | /dreal4/setup/ubuntu/18.04/install_prereqs.sh \
        && apt-get install -y --no-install-recommends apt-utils python3-dev python3-wheel python3-setuptools python3-pip python-zipstream \
        && rm -rf /var/lib/apt/lists/* \
        && apt-get clean all \
  # Build dReal4
  
negative.code: FROM       ubuntu:20.04
  
  RUN mkdir /dreal4
  COPY . /dreal4
  