1) Matrix theory 
In astronomical and geodetic calculations, Cracovians are a clerical convenience introduced in the 1930s by Tadeusz Banachiewicz for solving systems of linear equations by hand. Such systems can be written as Ax = b in matrix notation where x and b are column vectors and the evaluation of b requires the multiplication of the rows of A by the vecto...
• (a.) Of or pertaining to Cracow in Poland.
Cra·co'vi·an adjective Of or pertaining to Cracow in Poland. 
A mathematical symbol used in cracovian calculus