a class of data that follows the same data path through the program
a maximal set of dtokens having the same occurrence vector
a maximal set of tokens having the same occurrence-vector
a set composed of all of the objects equivalent to each other under an equivalence relation
a set of collating elements that all sort to the same primary location
a set of columns that are known to be equal and hence can be used interchangeably in other predicates or scalar expressions
a set of test cases such that any one member of the class is representative of any other member of the class
a set of values that should all be treated the same
(for an equivalence predicate) A set of objects, or potential objects, that are all the same under the specified equivalence predicate and different under that predicate from all objects not in the equivalence class. See also Tables on page 122.
A maximal set of objects that can all be transformed to each other by some type of transformation.
(1) A grouping of characters that are considered equal for the purpose of collation; for example, many languages place an uppercase character in the same equivalence class as its lowercase form, but some languages distinguish between accented and unaccented character forms for the purpose of collation. IBM. (2) A set of collating elements with the same primary collation weight. Elements in an equivalence class are typically elements that naturally group together, such as all accented letters based on the same base letter. The collation order of elements within an equivalence class is determined by the weights assigned on any subsequent levels after the primary weight. X/Open.