Dodgson condensation

In mathematics, Dodgson condensation is a method of computing the determinants of square matrices. It is named for its inventor, Charles Dodgson (better known as Lewis Carroll). The method in the case of an n × n matrix is to construct an (n − 1) × (n − 1) matrix, an (n − 2) × (n − 2), and so on, finishing with a 1 × 1 matrix, which has one entry, the determinant of the original matrix.