A class of operators arising in equations named for this operation are defined by being invertible modulo compact operators, and have finite-dimensional kernel and cokernel. The supremum over all r of “one over the volume of a ball of radius r,” times this operation applied to a function f, defines the Hardy-Littlewood maximal (15[2])function. A class of equations named for this operation includes Volterra and Fredholm (-5[1])equations. (15[1])The norm (15[2])on an L-p space is defined as this operation applied to “the (*) absolute value of f to the p,” all raised to “one over p.” The dominated (10[1])convergence theorem gives conditions for when a form of this operation can be interchanged with limits. (10[1])That form of this operation is taken with respect to a measure mu. (10[1])For 10 points, name this operation computed by summing areas of rectangles in the (10[1])Riemann definition. ■END■ (10[1])