When removal of a box changes the solution, it cannot remove the old solution; it can only allow more possible new solutions. Conversely, adding boxes can only narrow down between existing solutions.
Adjacent-numbered pages: BP829 BP830 BP831 BP832 BP833  *  BP835 BP836 BP837 BP838 BP839
meta (see left/right), miniproblems, creativeexamples, presentationmatters, assumesfamiliarity, structure
boxes_bpimage_three_per_side [smaller | same | bigger]
Aaron David Fairbanks