I also support to keep the problem in the library. Ch. Heckman is right, anything may happen inside the innermost contour. However, to solve real world problems we never have analytical representation of functions. And even in this case we want to interpret numerical data. Imagine any output of finite element simulation. For these problems we typically assume that if the value of a quantity increases when approaching a point, there is no sudden drop inside the innermost contour.
If I remember correctly, there is a section in PGML file for comments and these comments are visible when browsing OPL library. So it is possible to keep a message there. Something like "The problem assumes that the function values can be predicted from the contours. Do not use this problem if you are not satisfied with this assumption."
Of course, the graphs for Library/Michigan/Chap15Sec1/Q21.pg could be better (include colors, do not include numbers on axes). And Library/Michigan/Chap15Sec2/Q03.pg could mention the tolerance used to evaluate the answer. But this is another story.
If I remember correctly, there is a section in PGML file for comments and these comments are visible when browsing OPL library. So it is possible to keep a message there. Something like "The problem assumes that the function values can be predicted from the contours. Do not use this problem if you are not satisfied with this assumption."
Of course, the graphs for Library/Michigan/Chap15Sec1/Q21.pg could be better (include colors, do not include numbers on axes). And Library/Michigan/Chap15Sec2/Q03.pg could mention the tolerance used to evaluate the answer. But this is another story.