English
There is a natural equivalence between the set of associates of R and the set of principal ideals of R; it sends the class of x to the principal ideal (x) and has an inverse sending a principal ideal to its generator.
Русский
Существует естественное эквивалентное соответствие между эквивалентностями элементов и главными идеалами: класс x ↦ (x) и обратно.
LaTeX
$$"associatesEquivIsPrincipal" : Associates(R) ≃ { I : Ideal(R) // IsPrincipal I }$$
Lean4
/-- A proper ideal `I` is primary as a submodule. -/
abbrev IsPrimary (I : Ideal R) : Prop :=
Submodule.IsPrimary I