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This paper investigates the dynamic response of an elastic single-degree-of-freedom oscillator coupled with a rocking wall. Both configurations of a stepping rocking wall and a pinned rocking wall that have been reported in the literature are examined. The full nonlinear equations of motions are derived, and the paper shows through a comprehensive parametric analysis that the coupling with a rocking wall has mixed results on suppressing the dynamic response of the elastic oscillator. The stepping rocking wall is most effective in suppressing displacements of relative flexible structures with a heavier wall being most effective. In contrast, the pinned wall amplifies the displacements along a wide range of the spectrum with a heavier wall being most detrimental. This happens partly because in a pinned wall the moment from its weight works against stability. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, the fast synchronization problem of 5D Hindmarsh-Rose neuron networks is studied. Firstly, the global predefined-time stability of a class of nonlinear dynamical systems is investigated under the complete beta function. Then an active controller via backstepping design is proposed to achieve predefined-time synchronization of two 5D Hindmarsh-Rose neuron networks in which the synchronization time of each state variable of the master-slave 5D Hindmarsh-Rose neuron networks is different and can be defined in advance, respectively. To show the applicability of the obtained theoretical results, the designed predefined-time backstepping controller is applied to secure communication to realize asynchronous communication of multiple different messages. Three numerical simulations are provided to validate the theoretical results. [ABSTRACT FROM AUTHOR]

In this paper, some basic properties of soft hypervector spaces are studied with respect to some well-known operations such as intersection, union, and, or, product and sum. Also, the behavior of them is investigated under linear transformations and b-linear transformations. [ABSTRACT FROM AUTHOR]

One of the main results stated in Theorem 4.4 of our article, which appears in Trans. Amer. Math. Soc. 372 (2019), no. 10, 7191-7223, is that the structure algebra K[M(X,r)], over a field K, of a finite bijective left non-degenerate solution (X,r) of the Yang-Baxter equation is a module-finite central extension of a commutative affine subalgebra. This is proven by showing that the structure monoid M(X,r) is central-by-finite. This however is not true, even in case (X,r) is a (left and right) non-degenerate involutive solution. The proof contains a subtle mistake. However, it turns out that the monoid M(X,r) is abelian-by-finite and thus the conclusion that K[M(X,r)] is a module-finite normal extension of a commutative affine subalgebra remains valid. In particular, K[M(X,r)] is Noetherian and satisfies a polynomial identity. The aim of this paper is to give a proof of this result. In doing so, we also strengthen Lemma 5.3 (and its consequences, namely Lemma 5.4 and Proposition 5.5) showing that these results on the prime spectrum of the structure monoid hold even if the assumption that the solution (X,r) is square-free is omitted. [ABSTRACT FROM AUTHOR]

In previous work it was shown that the lower triangular generalized Hausdorff matrix Hαa with nonzero entries hnk= (n+α+1)-1, for a ≥ 0, is subnormal on Ι² if and only if α=0,1,2, …. For 0h : ..., is subnormal when .... In this paper we show that, when dj = Γ( j+1)Γ(h)/Γ( j+h), the square of the weights chosen above, then the corresponding operator Ch is bounded on Ι² for 0 < h < 3/2, that Hα is bounded on Ι² for all non-integer α < 0, and that Ch is closely related to Hh-1. This relationship leads to our main result that Ch is only subnormal when h = 1, when it corresponds to the original Cesaro operator with α = 0 and each dj = 1. [ABSTRACT FROM AUTHOR]

In this paper, I generalize Holzer's theorem for semi-diagonal equation. [ABSTRACT FROM AUTHOR]

The quasilinear parabolic equation with an absorption potential is considered: ..., where Ω is a bounded smooth domain in Rn, n ≥ 1, b is an absorption potential which is a continuous function such that b(t, x) > 0 in [0, T) x ≥ and b(t, x) ≡ 0 in {T} x ≥. In the paper, the conditions for b(t, x) that guarantee the uniform boundedness of an arbitrary weak solution of the mentioned equation in an arbitrary subdomain ... are considered. Under the above conditions the sharp upper estimate for all weak solutions u is obtained. The estimate holds for the solutions of the equation with arbitrary initial and boundary data, including blow-up data (provided that such a solution exists), namely, u = ∞ on {0} x ≥, u = ∞ on (0, T) x ∂≥. [ABSTRACT FROM AUTHOR]

The blended solutions are more general than the unblended solutions for polynomial-like iterative equation with multivalued functions. In this paper we study the blended solutions of polynomial-like iterative equation with multivalued functions. [ABSTRACT FROM AUTHOR]

A one-sided limit order book is modeled as a noncooperative game for several players. Agents offer various quantities of an asset at different prices, competing to fulfill an incoming order, whose size is not known a priori. Players can have different payoff functions, reflecting different beliefs about the fundamental value of the asset and probability distribution of the random incoming order. In a previous paper, the existence of a Nash equilibrium was established by means of a fixed point argument. The main issue discussed in the present paper is whether this equilibrium can be obtained from the unique solution to a two-point boundary value problem, for a suitable system of discontinuous ordinary differential equations. Some additional assumptions are introduced, which yield a positive answer. In particular, this is true when there are exactly two players, or when all players assign the same exponential probability distribution to the incoming order. In both of these cases, we also prove that the Nash equilibrium is unique. A counterexample shows that these assumptions cannot be removed, in general. [ABSTRACT FROM AUTHOR]

In this paper, we prove the following differential analog of the Noether normalization lemma: for every d-dimensional differential algebraic variety over differentially closed field of zero characteristic there exists a surjective map on to the d-dimensional affine space. Equivalently, for every integral differential algebra A over differential field of zero characteristic there exist differentially independent b1, . . . , bd such that A is differentially algebraic over subalgebra B differentially generated by b1, . . . , bd, and whenever p ⊂ B is a prime differential ideal, there exists a prime differential ideal q ⊂ A such that p = B ∩ q. We also prove the analogous theorem for differential algebraic varieties over the ring of formal power series over an algebraically closed differential field and present some applications to differential equations. [ABSTRACT FROM AUTHOR]

Text Let K be a complete, algebraically closed, non-Archimedean valued field, and let ϕ ∈ K ( z ) with deg ⁡ ( ϕ ) ≥ 2 . In this paper we consider the family of functions ord Res ϕ n ( x ) , which measure the resultant of ϕ n at points x in P K 1 , the Berkovich projective line, and show that they converge locally uniformly to the diagonal values of the Arakelov–Green's function g μ ϕ ( x , x ) attached to the canonical measure of ϕ . Following this, we are able to prove an equidistribution result for Rumely's crucial measures ν ϕ n , each of which is a probability measure supported at finitely many points whose weights are determined by dynamical properties of ϕ . Video For a video summary of this paper, please visit https://youtu.be/YCCZD1iwe00 . [ABSTRACT FROM AUTHOR]

R. Coleman and K. McMurdy calculated the stable reduction of X0(p3) (p ≥ 13) on the basis of the rigid geometry in [8]. In the present paper, we determine the stable reduction of X0(p4) for primes p ≥ 13 on the basis of their idea. As irreducible components in the stable reduction of X0(p4), a certain number of copies of the Hermitian curve, with an affine equation ap - a = tp+1, appear. [ABSTRACT FROM AUTHOR]

This paper describes how to analyse translinear topologies whose response is modified by the body effect by means of the general translinear principle. It proposes two different strategies for obtaining the translinear loop equations from each closed translinear set. Both strategies are tested analysing three topologies, one of them including some transistors in triode. From the results of such analysis, a fast analysis method for topologies with all transistor bodies connected to the same potential is also proposed. Simulated results are given showing good agreement with theoretical expressions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We study existence and multiplicity of solutions to the following bi-nonlocal p( x)-Kirchhoff equation via Krasnoselskii's genus, on the Sobolev space with variable exponent [ABSTRACT FROM AUTHOR]

Abstract In this paper, we consider the following nonlinear waveequation with variable exponents: u t t − div (| ∇ u | r (⋅) − 2 ∇ u) + | u t | m (⋅) − 2 u t = 0. By using a lemma by Komornik, we prove the decay estimates for the solution under suitable assumptions on the variable exponents m , r and the initial data. We also give two numerical applications to illustrate our theoretical results. [ABSTRACT FROM AUTHOR]

Let F q denote the finite field of order q . In this paper, some new classes of permutation polynomials of the form ( x p m − x + δ ) s + x over F p 2 m are obtained by determining the number of solutions of certain equations. [ABSTRACT FROM AUTHOR]

A ring R is said to be left uniquely generated if R a = R b in R implies that a = u b for some unit u in R . These rings have been of interest since Kaplansky introduced them in 1949 in his classic study of elementary divisors. Writing l ( b ) = { r ∈ R | r b = 0 } , a theorem of Canfell asserts that R is left uniquely generated if and only if, whenever R a + l ( b ) = R where a , b ∈ R , then a − u ∈ l ( b ) for some unit u in R . By analogy with the stable range 1 condition we call a ring with this property left annihilator-stable. In this paper we exploit this perspective on the left UG rings to construct new examples and derive new results. For example, writing J for the Jacobson radical, we show that a semiregular ring R is left annihilator-stable if and only if R / J is unit-regular, an analogue of Bass' theorem that semilocal rings have stable range 1. [ABSTRACT FROM AUTHOR]

Sixty (35 girls) ninth graders were assessed on measures of algebraic reasoning and usage of visual and symbolic representations (with a prompt for visual use) to solve equations and inequalities. The study grouped visual representations into two categories: arithmetic-visual, which entailed the use of real-world objects to represent specific values of variables, and algebraic-visual, which involved formal representations like the number line and the coordinate plane. Symbolic representations, on the other hand, encompassed the use of standard algorithms to solve equations, such as changing the place of terms in an equation. The results reveal that the use of algebraic visuals, as opposed to arithmetic visuals, was associated with enhanced algebraic reasoning. Further, although the students initially relied on standard algorithms to explain equations and inequalities, they could produce accurate algebraic-visual representations when prompted. These findings suggest that students have multiple representations of equations and inequalities but only express visual representations when asked to do so. In keeping with the general relationship between visuospatial abilities and mathematics, self-generated algebraic-visual representations partially mediated the relation between overall mathematics achievement and algebraic reasoning. [ABSTRACT FROM AUTHOR]

In this paper we consider the slightly L2-supercritical gKdV equations , with the nonlinearity and . In the previous work of the author, we know that there exists a stable self-similar blow-up dynamics for slightly L2-supercritical gKdV equations. Such solutions can be viewed as solutions with a single blow-up point. In this paper we will prove the existence of solutions with multiple blow-up points, and give a description of the formation of the singularity near the blow-up time. [ABSTRACT FROM AUTHOR]

This paper deals with the solvability of interval matrix equations in max-plus algebra. Max-plus algebra is the algebraic structure in which classical addition and multiplication are replaced by ⊕ and ⊗, where a ⊕ b = max ⁡ { a , b } and a ⊗ b = a + b . The notation A ⊗ X ⊗ C = B represents an interval max-plus matrix equation, where A , B , and C are given interval matrices. We define four types of solvability of interval max-plus matrix equations, i.e., the tolerance, weak tolerance, left-weak tolerance, and right-weak tolerance solvability. We derive the necessary and sufficient conditions for checking each of them, whereby all can be verified in polynomial time. [ABSTRACT FROM AUTHOR]

Tensor computation is intensive and difficult. Invariably, a vital component is the truncation of tensors, so as to control the memory and associated computational requirements. Various tensor toolboxes have been designed for such a purpose, in addition to transforming tensors between different formats. In this paper, we propose a simple Q-less QR truncation technique for tensors { x ( i ) } with x ( i ) ∈ R n 1 × ⋯ × n d in the simple and natural Kronecker product form. It generalizes the QR decomposition with column pivoting, adapting the well-known Gram–Schmidt orthogonalization process. The main difficulty lies in the fact that linear combinations of tensors cannot be computed or stored explicitly. All computations have to be performed on the coefficients α i in an arbitrary tensor v = ∑ i α i x ( i ) . The orthonormal Q factor in the QR decomposition X ≡ [ x ( 1 ) , ⋯ , x ( p ) ] = Q R cannot be computed but expressed as X R − 1 when required. The resulting algorithm has an O ( p 2 d n ) computational complexity, with n = max ⁡ n i . Some illustrative examples in the numerical solution of tensor linear equations are presented. [ABSTRACT FROM AUTHOR]

In the very recent work Wang and Wang (2014) proved that the initial value problem for the three dimension incompressible MHD equations has a global solutions ( u , B ) ∈ C ( [ 0 , ∞ ) ; χ − 1 ) , provided that the norms of the initial data are bounded exactly by the minimal value of the viscosity coefficients. In this paper, we prove that global solutions u , B that was obtained in Wang and Wang (2014) is asymptotic to zero in sense of the norm of the space χ − 1 as time goes to infinity. Moreover, stability of global solutions is also discussed. [ABSTRACT FROM AUTHOR]

A higher order Kirchhoff type equation ∫ R 2 m ( ∣ ∇ m u ∣ 2 + ∑ γ = 0 m − 1 a γ ( x ) ∣ ∇ γ u ∣ 2 ) d x ( ( − Δ ) m u + ∑ γ = 0 m − 1 ( − 1 ) γ ∇ γ ⋅ ( a γ ( x ) ∇ γ u ) ) = f ( x , u ) ∣ x ∣ β + ϵ h ( x ) in R 2 m is considered in this paper. We assume that the nonlinearity of the equation has exponential critical growth and prove that, for a positive ϵ which is small enough, there are two distinct nontrivial solutions to the equation. When ϵ = 0 , we also prove that the equation has a nontrivial mountain-pass type solution. [ABSTRACT FROM AUTHOR]

In the present paper we will ask for the lattice L(MVEx) of subvarieties of the variety defined by the set Ex(MV) of all externally com- patible identities valid in the variety MV of all MV-algebras. In particular, we will find all subdirectly irreducible algebras from the classes in the lattice L(MVEx) and give syntactical and semantical characterization of the class of algebras defined by P-compatible identities of MV-algebras. [ABSTRACT FROM AUTHOR]

In this paper, we consider the asymptotic behavior of solutions for nonlocal dispersal equation with non-homogeneous boundary conditions. We find that the long-time behavior is determined by the boundary value. [ABSTRACT FROM AUTHOR]

R. Coleman and K. McMurdy calculated the stable reduction of X0(p3) (p ≥ 13) on the basis of the rigid geometry in [8]. In the present paper, we determine the stable reduction of X0(p4) for primes p ≥ 13 on the basis of their idea. As irreducible components in the stable reduction of X0(p4), a certain number of copies of the Hermitian curve, with an affine equation ap - a = tp+1, appear. [ABSTRACT FROM AUTHOR]

We consider standard finite-dimensional variational models used in signal/image processing that consist of minimizing an energy involving a data fidelity term and a regularization term. We propose new contributions from a theoretical perspective which give a precise description on how the solutions of these optimization problems depend on the amount of smoothing effects and the data itself. The dependence of the minimal values of the energy is shown to be ruled by Hamilton-Jacobi equations, while the minimizers u(x,t) for the observed images x and smoothing parameters t are given by u(x,t) = x-tΔH(ΔxE(x,t)), where E(x,t) is the minimal value of the energy and H is a Hamiltonian related to the data fidelity term. Various vanishing smoothing parameter results are derived illustrating the role played by the prior in such limits. [ABSTRACT FROM AUTHOR]

Based on properties of Green's function and by Avery-Peterson fixed point theorem, the existence of multiple positive solutions are obtained for singular p-Laplacian fractional differential equation with infinite-point boundary conditions, and an example is given to demonstrate the validity of our main results. [ABSTRACT FROM AUTHOR]

Finding the solution of the absolute value equation (AVE) A x − | x | = b has attracted much attention in recent years. In this paper, we propose a relaxed nonlinear PHSS-like iterative method, which is more efficient than the Picard-HSS iterative method for the AVE, and is a generalization of the nonlinear HSS-like iteration method for the AVE. By using the theory of nonsmooth analysis, we prove the convergence of the relaxed nonlinear PHSS-like iterative method for the AVE. Numerical experiments are given to demonstrate the feasibility, robustness and effectiveness of the relaxed nonlinear HSS-like method. [ABSTRACT FROM AUTHOR]

Let R be a prime ring with center Z(R). Suppose that R admits a generalized semiderivation F with associated derivation d 6= 0. In the present paper we investigate the commutativity of a prime ring R satisfying any one of the identities: (i) F([x; y]) 2 Z(R), (ii) F(x-y) 2 Z(R), (iii) F(xy)-xy 2 Z(R), (iv) F(xy) - yx 2 Z(R), (v) [F(x); F(y)] = 0; (vi) F(x) - F(y) = 0 for all x; y 2 R. [ABSTRACT FROM AUTHOR]

Copyright of Cahiers de Topologie et Geometrie Differentielle Categoriques is the property of Andree C. EHRESMANN and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We show how the derivation of the Derrida–Lebowitz–Speer–Spohn equation can be prolonged to obtain a new equation, generalizing the models obtained in the paper by these authors. We then investigate its properties from both an analytical and numerical perspective. Specifically, a numerical method is presented to approximate solutions of the prolonged equation. Using this method, we investigate the relationship between the solutions of the prolonged equation and the Tracy–Widom GOE distribution. [ABSTRACT FROM AUTHOR]

We prove that all entire smooth strictly convex self-shrinking solutions on |$\mathbb{R}^n$| to the Hessian quotient flows must be quadratic. This generalizes the rigidity theorem for entire self-shrinking solutions to the Lagrangian mean curvature flow in pseudo-Euclidean space due to Ding– Xin [ 5 ]. Moreover, we show that our argument works for a larger class of equations. In particular, we obtain rigidity results for entire self-shrinking solutions on |$\mathbb{C}^n$| to the Kähler– Ricci flow under certain conditions. [ABSTRACT FROM AUTHOR]

Over the last two decades, the significance of academic achievement for students with disabilities in K-12 education has increased. To meet the needs of this population, educators turned to innovative strategies and technologies for instructional support in the classroom. For students with a learning disability, the need for such solutions is vital to address many of the academic struggles they face in the area of mathematics education. One evidence-based strategy shown to support instruction for students with a learning disability is the use of manipulatives. Although concrete manipulatives were extensively studied for this population, the virtual form of this technology lacks comparable research. Using a multiple probe design across three secondary students with a learning disability in mathematics, this study assessed the benefits of an instructional strategy using a virtual manipulative balance paired with explicit instruction to teach multistep linear equations. Results showed increased percent accuracy and independence scores for all three students across an intervention and maintenance phase. These findings and their broader implications for the field of mathematics education are discussed. [ABSTRACT FROM AUTHOR]

The equations in the Rosenzweig-MacArthur predator-prey model have been shown to be sensitive to the mathematical form used to model the predator response function even if the forms used have the same basic shape: zero at zero, monotone increasing, concave down, and saturating. Here, we revisit this model to help explain this sensitivity in the case of three response functions of Holling type II form: Monod, Ivlev, and Hyperbolic tangent. We consider both the local and global dynamics and determine the possible bifurcations with respect to variation of the carrying capacity of the prey, a measure of the enrichment of the environment. We give an analytic expression that determines the criticality of the Hopf bifurcation, and prove that although all three forms can give rise to supercritical Hopf bifurcations, only the Trigonometric form can also give rise to subcritical Hopf bifurcation and has a saddle node bifurcation of periodic orbits giving rise to two coexisting limit cycles, providing a counterexample to a conjecture of Kooji and Zegeling. We also revisit the ranking of the functional responses, according to their potential to destabilize the dynamics of the model and show that given data, not only the choice of the functional form, but the choice of the number and/or position of the data points can influence the dynamics predicted. [ABSTRACT FROM AUTHOR]

We show that the family of semi log canonical pairs with ample log canonical class and with fixed volume is bounded. [ABSTRACT FROM AUTHOR]

We prove an analog of the Szemerédi-Trotter Theorem in the plane for definable curves and points in any o-minimal structure over an arbitrary real closed field R. One new ingredient in the proof is an extension of the well known crossing number inequality for graphs to the case of embeddings in any o-minimal structure over an arbitrary real closed field. [ABSTRACT FROM AUTHOR]

On the complex projective line, we construct a Fuchs equation with four given finite singular points and with fundamental solution matrix that has given reducible 2×2 monodromy matrices in the nonresonance case. [ABSTRACT FROM AUTHOR]

We study the stability of stationary solutions of the two dimensional inviscid incompressible porous medium equation (IPM). We show that solutions which are near certain stable stationary solutions must converge as t → ∞ to a stationary solution of the IPM equation. It turns out that linearizing the IPM equation about certain stable stationary solutions gives a non-local partial damping mechanism. On the torus, the linearized problem has a very large set of stationary (undamped) modes. This makes the problem of long-time behavior more difficult since there is the possibility of a cascading non-linear growth along the stationary modes of the linearized problem. We solve this by, more or less, doing a second linearization around the undamped modes, exploiting a special non-linear structure, and showing that the stationary modes can be controlled. [ABSTRACT FROM AUTHOR]

In this article, we are concerned with the SU(3) Chern-Simons theory in $$\mathbb {R}^2$$ . It is believed that the self-dual equations of the theory possess three types of solutions, classified according to their (spatial) limiting behaviors. Solutions corresponding to the topological and the nontopological limiting behaviors have been shown to exist in the literature under various conditions. However, solutions satisfying the third limiting behavior, which we call mixed type solutions, have not yet been shown to exist explicitly. The purpose of this article is to show the existence of these mixed type solutions in a radially symmetric situation using the variational analysis incorporated with the bubbling argument. [ABSTRACT FROM AUTHOR]

Formal mathematics is a paragon of abstractness. It thus seems natural to assume that the mathematical expert should rely more on symbolic or conceptual processes, and less on perception and action. We argue instead that mathematical proficiency relies on perceptual systems that have been retrained to implement mathematical skills. Specifically, we investigated whether the visual system-in particular, object-based attention-is retrained so that parsing algebraic expressions and evaluating algebraic validity are accomplished by visual processing. Object-based attention occurs when the visual system organizes the world into discrete objects, which then guide the deployment of attention. One classic signature of object-based attention is better perceptual discrimination within, rather than between, visual objects. The current study reports that object-based attention occurs not only for simple shapes but also for symbolic mathematical elements within algebraic expressions-but only among individuals who have mastered the hierarchical syntax of algebra. Moreover, among these individuals, increased object-based attention within algebraic expressions is associated with a better ability to evaluate algebraic validity. These results suggest that, in mastering the rules of algebra, people retrain their visual system to represent and evaluate abstract mathematical structure. We thus argue that algebraic expertise involves the regimentation and reuse of evolutionarily ancient perceptual processes. Our findings implicate the visual system as central to learning and reasoning in mathematics, leading us to favor educational approaches to mathematics and related STEM fields that encourage students to adapt, not abandon, their use of perception. [ABSTRACT FROM AUTHOR]

We prove a differential Harnack inequality for the Endangered Species Equation, which is a nonlinear parabolic equation. Our derivation relies on an idea related to the parabolic maximum principle. As an application of this inequality, we will show that positive solutions to this equation must blow up in finite time. [ABSTRACT FROM AUTHOR]

We consider a system of nonhomogeneous linear impulsive pantograph equations. Sufficient conditions for the asymptotic constancy of the solutions are obtained. Moreover, in a special case, the limit of the solution is formulated in terms of a solution of an integral equation. [ABSTRACT FROM AUTHOR]

We consider a number of linear and non-linear boundary value problems involving generalized Schrödinger equations. The model case is -Δ u = V u for u ∈ W01,2( D) with D a bounded domain in ℝ n. We use the Sobolev embedding theorem, and in some cases the Moser-Trudinger inequality and the Hardy-Sobolev inequality, to derive necessary conditions for the existence of nontrivial solutions. These conditions usually involve a lower bound for a product of powers of the norm of V, the measure of D, and a sharp Sobolev constant. In most cases, these inequalities are best possible. [ABSTRACT FROM AUTHOR]

We generalize the notion of a laterally convergent net from increasing nets to general ones and study the corresponding lateral continuity of maps. The main result asserts that, the lateral continuity of an orthogonally additive operator is equivalent to its continuity at zero. This theorem holds for operators that send laterally convergent nets to any type convergent nets (laterally, order or norm convergent). [ABSTRACT FROM AUTHOR]

We determine the general form of the solutions of the five-dimensional vacuum Einstein equations with cosmological constant for which (i) the Weyl tensor is everywhere type II or more special in the null alignment classification of Coley et al, and (ii) the 3 × 3 matrix encoding the expansion, shear and twist of the aligned null direction has rank 2. The dependence of the solution on two coordinates is determined explicitly, so the Einstein equation reduces to PDEs in the three remaining coordinates, just as for four-dimensional (4d) algebraically special solutions. The solutions fall into several families. One of these consists of warped products of 4d algebraically special solutions. The others are new. [ABSTRACT FROM AUTHOR]