This operation is well defined for an operator if and only if it is in the first Schatten-class space. For an integral operator with kernel K, this operation equals the integral of K of x, x with respect to x. The special linear Lie algebra only contains elements for which this operation equals zero. When performing (-5[1])this operation on the product of matrices, it is invariant under a cyclic permutation of the product. This operation equals the coefficient of the second highest order term of the characteristic (10[1])polynomial. This operation (-5[1])equals the sum of a matrix's eigenvalues, (10[1]-5[1])and it (10[1])equals (-5[1])n for the n by n identity matrix. (10[1])This operation is invariant under taking transposes since the transpose does not change the leading diagonal. For 10 points, name this operation that for a matrix equals the sum of the leading diagonal's entries. ■END■ (10[2]0[2])