Sibirsk. Mat. Zh., 1980, Volume 21, Number 6

JOURNALS // Sibirskii Matematicheskii Zhurnal // Archive

1980, Volume 21, Number 6

	Памяти Михаила Алексеевича Лаврентьева		2
	Reduction of a hyperbolic equation to a symmetric hyperbolic system in the case of two space variables S. K. Godunov, V. I. Kostin		3
	Absence of closed asymptotic lines on tubes of negative curvature of a certain class B. E. Kantor		21
	Nontrivial solutions of equations with potential operators V. S. Klimov		28
	Quadrature formulas and the Poincaré–Bertrand formula for singular integrals I. K. Lifanov		46
	A problem with a directional derivative for multicomponent diffusion and chemical kinetics systems V. N. Maslennikova, N. V. Gapeeva		61
	Parametric representations of certain classes of functions that are regular in the upper half-plane L. Kh. Megrabyan		71
	Rank functions in stable theories T. G. Mustafin		84
	Some properties of expansions in generalized eigenfunctions of Carleman selfadjoint operators Yu. B. Orochko		96
	Integral representations of differentiable functions in domains with a nonsmooth boundary Yu. G. Reshetnyak		108
	On subquasi-varieties of nilpotent minimal nonabelian group varieties A. N. Fedorov		117
	Approximation of multichannel queueing systems S. G. Foss		132
	Finite groups with a normalizer condition L. I. Shidov		141
	On Lewy's theorem on Hessian zeros of a harmonic function A. I. Yanushauskas		146
	Surfaces with a given curvature measure Yu. D. Burago		153
	Rigidly directed groups Z. I. Dimitrov		156
	Some properties of $B$-integral operators in $L_2$ V. B. Korotkov		161
	Properties of approximate solutions of nonlinear equations of variable type M. M. Lavrent'ev (Jn.)		165
	On the solutions of some system of functional equations in the class of meromorphic functions L. I. Il'evskii		176
	Factorizations of locally finite groups N. S. Chernikov		186
	Decidable fragments of universal theories and existentially closed models O. V. Belegradek		196
	Dense subgroups of locally compact abelian groups M. I. Kabenyuk		202
	Analytic continuation of the sum of Laplace series O. M. Logunova		204
	Some extremal properties of typically real functions V. V. Chernikov		208