... 2, }.The set of positive integers: N+= { 1, 2, 3, }.The set of integers: Z = { 0, − 1, 1, − 2, 2, }.The set of rational numbers: Q =±mn: m, n ∈ N,n=0.For the purposes of this preliminary ... reciprocation, or inversion, on R\ {0}such that for all x, y, z ∈ R,x + y = y + x,(x + y)+z = x +(y + z) , 0+x = x,x +(−x)= 0, xy = yx,(xy) z = x (yz) , x(y + z)=xy + xz,1x = x, and xx−1=1ifx ... maximumelement of S, and is then a least upper bound of S. The maximum element,if it exists, of S is also called the largest,orgreatest,elementofS.An element b ∈ X is called a lower bound, or minorant, of...