“…We denote a complete orthonormal system in L 2 (0, 1) of eigenfunctions and eigenvalues by (0 n (e, cr), A w (e, cr)} , where /^(e, cr) > A 2 (e, a) > /1 3 (£, a) > •••. The principal eigenvalue A^e, cr) approaches zero as e ->0, and there exists a constant /c/j > 0 such that all other ones are less than -fjt 1 . Let E denote the orthogonal projection onto span {^(e, cr)}, that is, Eu = (tt^jCe, cr)) L 2 (0 >1) 0 1 (e, a).…”