English
GroupSeminorm E carries a function-like structure: each p ∈ GroupSeminorm E acts as a function p: E → ℝ, and equality is detected by their values on all inputs.
Русский
GroupSeminorm E имеет структуру, подобную функции: каждый p ∈ GroupSeminorm E действует как функция p: E → ℝ, и равенство определяется значениями на всех аргументах.
LaTeX
$$\\text{GroupSeminorm } E \\text{ is function-like with } \\text{coe } p := p.toFun, \\text{ and } p.toFun = q.toFun \\Rightarrow p = q$$
Lean4
@[to_additive]
instance funLike : FunLike (GroupSeminorm E) E ℝ
where
coe f := f.toFun
coe_injective' f g h := by cases f; cases g; congr