aybx

AyBx is a notation that appears in various mathematical and technical contexts without a single, universal definition. In general, it is used to denote a quantity that depends on two indices or parameters, often written as a two-parameter family or a two-dimensional array. The exact meaning of AyBx is determined by the surrounding context and should be clarified in the source where it is introduced.

Common interpretations include:

- as a value of a function f defined on a product set Y×X, with AyBx representing the function evaluated at the pair (y, x);

- as an entry in a two-dimensional structure, where the row is indexed by y and the column by x, so AyBx denotes the element located at that position;

- as a product or combination of two parameterized families, such that AyBx encodes a quantity derived from the y-th member of one family and the x-th member of another.

Because AyBx is not standardized, authors typically define it explicitly at first use to avoid ambiguity. For example, a paper might state AyBx = A_y f(B_x) or AyBx = A_y B_x, depending on the operation or object under study. When encountering AyBx, readers should look for definitions of the indices y and x, the nature of the dependence, and any operations implied by the notation.

See also: notation for functions on product spaces, index notation, two-parameter families.