We investigate the intersection R of two permutable Hermitian surfaces of PG(3, q2), q odd. We show that R is a determinantal variety. From the combinatorial point of view R comprises a complete (q2 + 1)-span of the two corresponding Hermitian surfaces.

This paper is devoted to the study of linear systems of neutral differential equations with delay. Assuming the linear parts to be given by pairwise permutable matrices, representation of a solution of a nonhomogeneous initial value problem using matrix polynomial of a degree depending on time is derived. Examples illustrating the obtained results are given.

This paper gives an analysis explaining various cases where the scope of two logical operators is non-permutable in a sentence. The explanation depends on a theory of derivational economy couched in the synchronous tree adjoining grammar framework. Locality restrictions made using the STAG formalism allow us to limit the computational complexity of using transderivational constraints and allows...

If H is a subgroup of the symmetric group $4, then a 3-groupoid (S, f ) is called H-permutable if f ( x ~ ( 1 ) , X a ( 2 ) , X ~ r ( 3 ) ) = X~(4) ~ f ( x l , x2 ,x3 ) = x4 for every cr C H. Some classes of generalized idempotent H-permutable 3-groupoids are equivalent to Steiner, Mendelsohn and other quadruple systems. We prove that the variety of generalized idempotent H-permutable 3-groupoi...

a subgroup $h$ is said to be $s$-permutable in a group $g$‎, ‎if‎ ‎$hp=ph$ holds for every sylow subgroup $p$ of $g$‎. ‎if there exists a‎ ‎subgroup $b$ of $g$ such that $hb=g$ and $h$ permutes with every‎ ‎sylow subgroup of $b$‎, ‎then $h$ is said to be $ss$-quasinormal in‎ ‎$g$‎. ‎in this paper‎, ‎we say that $h$ is a weakly $ss$-quasinormal‎ ‎subgroup of $g$‎, ‎if there is a normal subgroup ...

We've been able to show recently that Permutable Chebyshev polynomials (T polynomials) defined over the field of real numbers can be used to create a Diffie-Hellman-like key exchange algorithm and certificates. The cryptosystem was theoretically proven to withstand attacks using quantum computers. We additionally prove that attacks based on the inverse of the cosine representation of T polynomi...