permod

Permod is a term used in several disciplines without a single, universally accepted definition. In mathematical discussions it has sometimes been used as shorthand for notions that combine permutation operations with modular arithmetic, but the specifics vary by author.

One common interpretation is permutation modulo n, a construction that considers the action of permuting a set while imposing a modulus on element indices or on permutation statistics. In this sense, permod may refer to equivalence classes of permutations under a modular constraint, or to functions that map permutations to residues modulo n.

In computer science and software engineering, permod has appeared as the name of a hypothetical library, or as a project acronym standing for permutation-modular utilities. In documentation, it may denote utilities that generate or apply permutations with constraints derived from modular arithmetic, such as restricting indices to a residue class or composing permutations within a modular arithmetic framework.

In data analysis or cryptography contexts, similar-sounding terms are used to describe permutation-based transforms with modular properties, though such uses are not standardized under the term permod.

Because its meaning is context-dependent, readers encountering permod should consult the source material for a precise definition. See also permutation, modular arithmetic, modular permutation, and permutation group.