English
The multiplicative support of a function f : ι → M is the set of indices x with f(x) ≠ 1.
Русский
Мультипликативная поддержка функции f : ι → M набирается из индексов x, для которых f(x) ≠ 1.
LaTeX
$$$ \\mathrm{mulSupport}(f) = \\{ x \\mid f(x) \\neq 1 \\} $$$
Lean4
/-- `mulSupport` of a function is the set of points `x` such that `f x ≠ 1`. -/
@[to_additive /-- `support` of a function is the set of points `x` such that `f x ≠ 0`. -/
]
def mulSupport (f : ι → M) : Set ι :=
{x | f x ≠ 1}