Name the map argument in cores-range-⊆'s clause head

Address a review nit: the clause head now mirrors the type signature.  `m` is
unused in the body (the proof only inspects the membership proof), but naming it
saves the reader a trip to the signature to recover the argument order.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: williamdemeo

src-lib-exts/abstract-set-theory/Axiom/Set/Map/Extra.agda

@@ -711,7 +711,7 @@ module _  {A B : Type}
 -- The map `m` is an explicit argument because it cannot be recovered by unification:
 -- `_∣^_` goes through `⊆-map`, which mentions `m` only as `m ˢ` (i.e., `proj₁ m`).
 cores-range-⊆ : ∀ {A B : Type} ⦃ _ : DecEq B ⦄ (m : A ⇀ B) {X : ℙ B} → range (m ∣^ X) ⊆ X
-cores-range-⊆ _ b∈range with Equivalence.from ∈-map b∈range
+cores-range-⊆ m b∈range with Equivalence.from ∈-map b∈range
 ... | _ , refl , ab∈cores = proj₁ (Equivalence.from ∈-filter ab∈cores)