Two typos in the model solutions for HW 6.  Obviously the course
staff were also getting burnt out right before break.

Problem 1b: it's the point exactly at the midpoint of the line
segment.  The comment about "integer coordinates" is wrong.  The rest
of the problem involves only points with integer coordinates, but this
part specifically said the coordinates didn't need to be integers
(so that it would be easier to answer).

Problem 2a: In the second sentence of the solution, a pair of set
brackets got dropped.  The sentence So the co-domain of g can be
defined as {1,...x | x in Z+} should actually be So the co-domain of g
can be defined as {{1,...x} | x in Z+}

Sorry

Margaret