An involutive bisemilattice is an algebra of type satisfying:
;
;
;
;
;
;
;
.
Suppose and . Then say that points to and write when they share a position:
(The use of โpointโ here is unrelated to the โpointed setsโ from Notation 2.1.3 .)
The (first-order) differential calculus over an algebra over a field is a pair , where is a bimodule over , is a linear map , which satisfies the Leibniz rule,
(2.1) |
and is generated as a left module by the image of . We say that is connected if .
We say that the connection is star-compatible, if:
where , i.e. is the induced -structure on higher tensors.
We say that the metric is compatible with the higher-order differential calculus iff , that is
A linear connection is compatible with the metric if
(5.1) |
Let be a set with two operations and such that is a semigroup (not necessarily commutative) and is an inverse semigroup. Then, we say that is a left inverse semi-brace if
(1) |
holds, for all
.
We call
and
the
additive semigroup
and the
multiplicative semigroup
of
, respectively.
A right inverse semi-brace is defined similarly, by replacing condition (
1
) with
for all
.
A two-sided inverse semi-brace
is a left inverse semi-brace that is also a right inverse semi-brace with respect to the same operations
and
.
A locally Lipschitz function is path-differentiable if for each Lipschitz 1 1 1 In other parts of the literature (see e.g. [ 4 ] ), this definition is given with absolutely-continuous curves, and this is equivalent because such curves can be reparameterized (for example, by arclength) to obtain Lipschitz curves, without affecting their role in the definition. curve , for almost every , the composition is differentiable at and the derivative is given by
for all .
Let โ โ be a bilinear product in a vector space Suppose that it satisfies the following law:
(2.3) |
Then, we call the pair an antiassociative algebra . Combining both associative (q=1) and antiassociative (q=-1) cases, any algebra satisfying
is called a -associative algebra .
[ 12 ] An algebra over is called mock Lie if it is commutative:
(2.4) |
and satisfies the Jacobi identity:
(2.5) |
for any , , .
Let be an antiassociative algebra. We say that is a sympletic antiassociative algebra if is a non-degenerate skew-symmetric bilinear form on such that the following identity satisfied:
(5.2) |
for all
We will say that is a -null element if for all we have
(2.1) |
Let be a probability measure on with the product metric
Define the marginal distributions by and . If the marginals are independent, we write . We denote by the product -algebra generated by the measurable rectangles for and .
Let be a commutative unital ring. The set of idempotents is a Boolean algebra, denoted by , with operations
It carries a partial ordering defined by (which is -definable). The atoms of are the minimal idempotents (with respect to the ordering) that are not equal to . (In fact we assume ).
Let be a Frรฉchet space and be a function on a subset . We say that the differential equation
(12) |
satisfies local uniqueness of Carathรฉodory solutions if the following holds: For all Carathรฉodory solutions and of ( 12 ) and such that , there exists an interval which is an open neighbourhood of in such that
Let be a -manifold modelled on a Frรฉchet space and be a function on a subset such that for all . We say that a function on a non-degenerate interval is a Carathรฉodory solution to the differential equation
(16) |
if is absolutely continuous, for all and
for -almost all (using notation as in 2.4 ). If is given and satisfies, moreover, the condition , then is called a Carathรฉodory solution to the initial value problem
(17) |
Let be a smooth function and a compact, codimension-one manifold with a boundary . The manifold is a ridge of the scalar field if both and are normally attracting invariant manifolds for the gradient system
(VI.4) |
Let be the reduced loop class of the circle in Figure 3.1 . The Big circle relation is
(4.5) |
[ 24 ] An associative dialgebra is a vector space together with bilinear maps satisfying the following identities
A Nelson algebra is an algebra of type such that the following conditions are satisfied for all :
,
,
,
,
,
,
,
.
An algebra of type is said to be a dually hemimorphic semi-Heyting algebra if is a semi-Heyting algebra and the following equations are satisfied:
,
,
.
An algebra of type is said to be a dually hemimorphic semi-Nelson algebra if is a semi-Nelson algebra and the following equations are satisfied:
,
,
,
,
,
,
.
We use the convention that the unary operation has higher priority than , so the expression means .
[ 8 ] Let be a Riemennian manifold. Then a complex-valued function is said to be an eigenfunction if it is eigen both with respect to the Laplace-Beltrami operator and the conformality operator i.e. there exist complex numbers such that
A set of complex-valued functions is said to be an eigenfamily on if there exist complex numbers such that for all we have
Let be an abelian group. A map is called a skew-symmetric bicharacter on if the following identities hold,
,
,
,
.
A (multiplicative) hom-Lie algebra is a triplet , where is a vector space equipped with a skew-symmetric bilinear map , and a linear map satisfying such that
(2.1) |
Furthermore, if is a vector space automorphism of , then the hom-Lie algebra is called a regular hom-Lie algebra.
( [ 21 ] ) A representation of a hom-Lie algebra on a -vector space with respect to is a linear map such that
(2.2) |
(2.3) |
for all and .
Let be a commutative ring, and a -linear category. Let be a functor that preserves finite products, and . An endomorphism is a machine if, for all morphisms , there exists a unique such that:
We call the stable state of with initial condition , and denote by the stable state of with initial condition .
Let be as in definition 1 . Let . We say that does not depend on if, for any , for any pair of maps , and for all , the following holds:
(4) |
Otherwise, we say that depends on .
Let be a -group. Let be, simultaneously, a -module and a -module. We say that is a - module if
(18) |
for . We denote by - the category whose objects are - modules and morphisms are the functions such that is both -linear and -linear.
Let , be two bounded distributive lattices. A structure is called a FDL-module, if is a function such that for every and every the following conditions hold:
,
,
,
.
A structure is called an IDL-module, if is a function such that for every and every the following conditions hold:
,
,
.
Moreover, a structure is called a FIDL-module, if is a FDL-module and is an IDL-module.
Let be an alphabet, , and a function such that
(1) |
Then, the folding function is a partial function defined by
(2) |
where , , , with for , and \textepsilon is the empty string.
is an extreme point of if and only if there are no points and no such that
(3) |
A Hom-coassociative coalgebra is a Hom-vector space together with a linear map satisfying
(1) |
A Hom-coassociative coalgebra as above may be denoted by or simply by . A Hom-coassociative coalgebra is called multiplicative if .
An infinitesimal Hom-bialgebra is a quadruple in which is a Hom-associative algebra, is a Hom-coassociative coalgebra and satisfying the following compatibility
(2) |
Define the static part of to be the part of that has not been pushed yet, i.e. the subword satisfying
Let be a -algebra with multiplication and let be a -algebra with multiplication . Let be linear maps. We call (or the quadruple ) an -bimodule -algebra if is an -bimodule that is compatible with the multiplication on in the sense that
for all .
( [ 19 ] , [ 20 ] ) A Novikov-Poisson algebra is a triple such that is a commutative associative algebra, is a Novikov algebra and the following compatibility conditions hold, for all :
(1.3) | |||
(1.4) |
A morphism of Novikov-Poisson algebras from to is a linear map satisfying and , for all .
( [ 15 ] ) A BiHom-Novikov algebra is a 4-tuple , where is a linear space, is a linear map and are commuting linear maps (called the structure maps of ), satisfying the following conditions, for all :
(1.6) | |||
(1.7) | |||
(1.8) |
A morphism of BiHom-Novikov algebras is a linear map such that , and , for all .
( [ 15 ] ) A BiHom-Novikov-Poisson algebra is a 5-tuple such that:
(1) is a BiHom-commutative algebra;
(2) is a BiHom-Novikov algebra;
(3) the following compatibility conditions hold for all :
(1.9) | |||
(1.10) | |||
(1.11) |
The maps and (in this order) are called the structure maps of .
A morphism of BiHom-Novikov-Poisson algebras is a map that is a morphism of BiHom-associative algebras from to and a morphism of BiHom-Novikov algebras from to .
( [ 16 ] ) A BiHom-Lie algebra is a 4-tuple in which is a linear space, are linear maps and is a bilinear map, such that
(4.1) | |||
(4.2) | |||
(4.3) | |||
(4.4) | |||
(BiHom-Jacobi condition) |
for all . The maps and (in this order) are called the structure maps of .
A BiHom-Poisson algebra is a 5-tuple , with the property that
(1) is a BiHom-commutative algebra;
(2) is a BiHom-Lie algebra;
(3) the following BiHom-Leibniz identity holds for all :
(4.5) |
Let be a BiHom-Novikov-Poisson algebra. Then is called left BiHom-associative if the following condition holds for all :
(4.6) |
Let be an algebraic number field of degree , and let be a -basis of for some primitive element . Given any element , we can write uniquely as
for some with . Then the degree of with respect to , written as , is the degree of .
[ 10 ] Let โ โ be a bilinear product in a vector space Suppose that it satisfies the following law:
(2.1) |
Then, we call the pair an antiassociative algebra .
[ 13 ] An algebra over is called JJ if it is commutative:
(2.2) |
and satisfies the Jacobi identity:
(2.3) |
for any , , .
[ 13 ] A vector space is a module over a JJ algebra , if there is a linear map (a representation) such that
(2.4) |
for any and .
Let be a JJ algebra. Two representations and of are said to be isomorphic if there exists a linear map such that
We say that is a superposition measure generated by if it is concentrated on the pairs such that
(10) |
for -almost every . We further say that a distributional solution of ( 8 ) is a superposition solution if there exists a superposition measure generated by such that for all times .