LETTER TO THE EDITOR

In my article (S. Ya. Yakubov, “Nonlocal Solvability of Boundary-Value Problems for Quasilinear Partial Differential Equations of Hyperbolic Type”), published in DAN, vol. 176, No. 2, 1967, the following corrections should be made to errors introduced through the author’s fault:

1. In the positivity condition for the form following formula (2), the factor ((-1)^m) has been omitted.

2. In the author’s notation (c(t, x, 0)), (m) should be replaced by (m - 1).

3. In condition (4^\circ) of Theorem 2, (W_2^m) should be replaced by (W_2^{2m}).

4. The function (\Phi(r)) in Theorems 2 and 3 must be real-valued.

5. The author can assert the validity of Theorem 3 only for
   (q = m(n - 2m)^{-1}).

6. Instead of the phrase “As is easy to see, . . .” on p. 282, the following should be inserted: “The results of our work ((^3)) make it possible to obtain for ((^9)) a local existence theorem for the mixed problem or the Cauchy problem for any (p \ge 0). As for the nonlocal theory, no new results are obtained.”

S. Ya. Yakubov