This is from Pinter's abstract algebra book. I am not getting this part clearly: " *From
one point of view the set of the integers, with addition and
multiplication, forms a ring (that is, it satisfies the axioms stated
previously). From another point of view it is an ordered set, and
satisfies special axioms of ordering. On a different level, the
positive integers form the basis of “recursion theory,” which singles
out the particular way positive integers may be constructed,
beginning with 1 and adding 1 each time* ."