Task: Text Categorization
Input (English): This multilinear function can be used to determine orientation in Euclidean spaces, and the Gram is a type of this obtained from integrals of functions. It can be used to find the eigenvalues of an endomorphism, and can be calculated recursively using cofactors, summing the minors multiplied by one or negative one. It is Abelian, while the structure it is calculated from is not, and is not invertible. The Wronskian is obtained from functions and derivatives. When it has a value of one, that structure is unimodular, a value of zero means that structure is singular, and it remains constant under the transpose operation. It is used in Cramer's Rule to solve systems of linear equations. For 10 points, name this mathematical object derived from matrices, which for a two by two matrix can be calculated as a*d - b*c.
Output (English): Science