Editing Pairing function (section)

== Shifted Cantor pairing function ==
The following pairing function: <math>\langle i, j\rangle := \frac{1}{2}(i+j-2)(i+j-1) + i</math>, where <math>i, j\in\{1, 2, 3, \dots \}</math>.<ref>{{harvtxt|Hopcroft|Ullman|1979|p=169}} cited in {{harv|Pigeon|loc=Equations 2, 3}}.</ref> is the same as the Cantor pairing function, but shifted to exclude 0 (i.e., <math>i=k_2+1</math>, <math>j=k_1+1</math>, and <math>\langle i, j\rangle - 1 = \pi(k_2,k_1)</math>).{{sfn|Pigeon|loc=Equation 8}} It was used in the popular computer textbook of Hopcroft and Ullman (1979).