refactor: Improve todos and remove ambiguous

HepLean/AnomalyCancellation/PureU1/BasisLinear.lean

@@ -75,7 +75,8 @@ lemma sum_of_vectors {n : ℕ} (f : Fin k → (PureU1 n).LinSols) (j : Fin n) :
     (∑ i : Fin k, (f i)).1 j = (∑ i : Fin k, (f i).1 j) :=
   sum_of_anomaly_free_linear (fun i => f i) j
 
-TODO "replace `Finsupp.equivFunOnFinite` here with `Finsupp.linearEquivFunOnFinite`."
+TODO "The definition of `coordinateMap` here may be improved by replacing
+   `Finsupp.equivFunOnFinite` with `Finsupp.linearEquivFunOnFinite`. Investigate this."
 /-- The coordinate map for the basis. -/
 noncomputable
 def coordinateMap : (PureU1 n.succ).LinSols ≃ₗ[ℚ] Fin n →₀ ℚ where

HepLean/AnomalyCancellation/PureU1/Permutations.lean

@@ -89,7 +89,7 @@ lemma FamilyPermutations_anomalyFreeLinear_apply (S : (PureU1 n).LinSols)
     ((FamilyPermutations n).linSolRep f S).val i = S.val (f.invFun i) := by
   rfl
 
-TODO "Replace the definition of `pairSwap` with `Equiv.swap`."
+TODO "Remove `pairSwap`, and use the Mathlib defined function `Equiv.swap` instead."
 /-- The permutation which swaps i and j. -/
 def pairSwap {n : ℕ} (i j : Fin n) : (FamilyPermutations n).group where
   toFun s :=

HepLean/AnomalyCancellation/PureU1/VectorLike.lean

@@ -10,7 +10,6 @@ import HepLean.AnomalyCancellation.PureU1.Sorts
 For the `n`-even case we define the property of a charge assignment being vector like.
 
 -/
-TODO "Define vector like ACC in the `n`-odd case."
 universe v u
 
 open Nat