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We consider the mixed problem for the quasilinear partial functional differential equation with unbounded delay $D_{t}z(t,x)={\sum }_{i=1}^n{f}_i(t,x,z_{(t,x)})D_{x_i}z(t,x)+h(t,x,z_{(t,x)})$, where $z_{(t,x)}\in X{̶}_0$ is defined by $z_{(t,x)}(\tau ,s)=z(t+\tau ,x+s)$, $(\tau ,s)\in (-\infty ,0]\times [0,r]$, and the phase space $X{̶}_0$ satisfies suitable axioms. Using the method of bicharacteristics and the fixed-point method we prove a theorem on the local existence and uniqueness of Carathéodory solutions of the mixed problem.

We consider the local initial value problem for the hyperbolic partial functional differential equation of the first order (1) $Dₓz(x,y)=f(x,y,z(x,y),\left(Wz\right)(x,y),D_{y}z(x,y))$ on E, (2) z(x,y) = ϕ(x,y) on [-τ₀,0]×[-b,b], where E is the Haar pyramid and τ₀ ∈ ℝ₊, b = (b₁,...,bₙ) ∈ ℝⁿ₊. Using the method of bicharacteristics and the method of successive approximations for a certain functional integral system we prove, under suitable assumptions, a theorem on the local existence of weak solutions of the problem (1),(2).

We seek for classical solutions to hyperbolic nonlinear partial differential-functional equations of the second order. We give two theorems on existence and uniqueness for problems with nonlocal conditions in bounded and unbounded domains.

Generalized solutions to quasilinear hyperbolic systems in the second canonical form are investigated. A theorem on existence, uniqueness and continuous dependence upon the boundary data is given. The proof is based on the methods due to L. Cesari and P. Bassanini for systems which are not functional.

We consider the mixed problem for the hyperbolic partial differential-functional equation of the first order $$D_{x}z(x,y)=f(x,y,z_{(x,y)},D_{y}z(x,y)),$$ where $z_{(x,y)}[-\tau ,0]\times [0,h]\to ℝ$ is a function defined by $z_{(x,y)}(t,s)=z(x+t,y+s)$, $(t,s)\in [-\tau ,0]\times [0,h]$. Using the method of bicharacteristics and the method of successive approximations for a certain integral-functional system we prove, under suitable assumptions, a theorem of the local existence of generalized solutions of this problem.

We consider a second order semilinear functional evolution equation with infinite delay in a Banach space. We prove the existence of mild solutions for this equation using the measure of noncompactness technique and the Schauder fixed point theorem.