Which of these are partitions of the set of real numbers?
a.the negative real numbers, {0}, the positive real numbers
b.the set of irrational numbers, the set of rational numbers
c.the set of intervals [k,k + 1], k = ...,−2,−1,0, 1,2,...
d.the set of intervals (k,k + 1), k = ...,−2,−1,0, 1,2,..?
