anchor.diff:  
   
   RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
  -   openintro_1.4.tar.gz \
  +   openintro_1.7.1.tar.gz \
      assertthat_0.2.0.tar.gz \
      R6_2.2.2.tar.gz \
      magrittr_1.5.tar.gz \
      lazyeval_0.2.1.tar.gz \
      DBI_0.7.tar.gz \
      tibble_1.3.4.tar.gz \
  -   glue_1.1.1.tar.gz \
  +   glue_1.2.0.tar.gz \
      pkgconfig_2.0.1.tar.gz \
      plogr_0.1-1.tar.gz \
      bindr_0.1.tar.gz \
      bindrcpp_0.2.tar.gz \
  -   dplyr_0.7.2.tar.gz 
  -
  -RUN rm \
  -   openintro_1.4.tar.gz \
  +   dplyr_0.7.4.tar.gz 
  +
  +RUN rm \
  +   openintro_1.7.1.tar.gz \
      assertthat_0.2.0.tar.gz \
      R6_2.2.2.tar.gz \
      magrittr_1.5.tar.gz \
  
positive.code:   
  # more libraries Mine Cetinakya-Rundel asked for
  RUN DEBIAN_FRONTEND=noninteractive wget \
     https://mirrors.nics.utk.edu/cran/src/contrib/openintro_1.4.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/tibble_1.3.4.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/bindr_0.1.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/bindrcpp_0.2.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/glue_1.1.1.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/pkgconfig_2.0.1.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/plogr_0.1-1.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/dplyr_0.7.2.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/assertthat_0.2.0.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/R6_2.2.2.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/magrittr_1.5.tar.gz \
  
negative.code:    tibble_1.3.4.tar.gz \
     bindr_0.1.tar.gz \
     bindrcpp_0.2.tar.gz \
     glue_1.2.0.tar.gz \
     pkgconfig_2.0.1.tar.gz \
     plogr_0.1-1.tar.gz \
     dplyr_0.7.4.tar.gz 
  
  RUN DEBIAN_FRONTEND=noninteractive wget \
     https://mirrors.nics.utk.edu/cran/src/contrib/chron_2.3-50.tar.gz \
  