Lean4
/-- We introduce a type alias for `HahnSeries` in order to work with scalar multiplication by
series. If we wrote a `SMul (HahnSeries Γ R) (HahnSeries Γ V)` instance, then when
`V = HahnSeries Γ R`, we would have two different actions of `HahnSeries Γ R` on `HahnSeries Γ V`.
See `Mathlib/Algebra/Polynomial/Module.lean` for more discussion on this problem. -/
@[nolint unusedArguments]
def HahnModule (Γ R V : Type*) [PartialOrder Γ] [Zero V] [SMul R V] :=
HahnSeries Γ V