refactor: Slight adjustments to doc-strings

HepLean/PerturbationTheory/WickContraction/InsertAndContract.lean

@@ -291,9 +291,15 @@ lemma insert_fin_eq_self (φ : 𝓕.FieldOp) {φs : List 𝓕.FieldOp}
   Wick contractions of `φs` with `φ` inserted at `i` is equal to the sum over Wick contractions
   `φsΛ` of just `φs` and the sum over optional uncontracted elements of the `φsΛ`.
 
-  In other words, `∑ (φsΛ : WickContraction (φs.insertIdx i φ).length), f φsΛ` is equal to
-  `∑ (φsΛ : WickContraction φs.length), ∑ (k : Option φsΛ.uncontracted), f (φsΛ ↩Λ φ i k) `.
-  where `(φs.insertIdx i φ)` is `φs` with `φ` inserted at position `i`. -/
+  In other words,
+
+  `∑ (φsΛ : WickContraction (φs.insertIdx i φ).length), f φsΛ`
+
+  where `(φs.insertIdx i φ)` is `φs` with `φ` inserted at position `i`. is equal to
+
+  `∑ (φsΛ : WickContraction φs.length), ∑ k, f (φsΛ ↩Λ φ i k) `.
+
+  where the sum over `k` is over all `k` in `Option φsΛ.uncontracted`. -/
 lemma insertLift_sum (φ : 𝓕.FieldOp) {φs : List 𝓕.FieldOp}
     (i : Fin φs.length.succ) [AddCommMonoid M] (f : WickContraction (φs.insertIdx i φ).length → M) :
     ∑ c, f c =

HepLean/PerturbationTheory/WickContraction/Sign/Basic.lean

@@ -22,7 +22,8 @@ open FieldStatistic
 /-- Given a Wick contraction `c : WickContraction n` and `i1 i2 : Fin n` the finite set
   of elements of `Fin n` between `i1` and `i2` which are either uncontracted
   or are contracted but are contracted with an element occurring after `i1`.
-  I.e. the elements of `Fin n` between `i1` and `i2` which are not contracted with before `i1`.
+  In other words, the elements of `Fin n` between `i1` and `i2` which are not
+  contracted with before `i1`.
   One should assume `i1 < i2` otherwise this finite set is empty. -/
 def signFinset (c : WickContraction n) (i1 i2 : Fin n) : Finset (Fin n) :=
   Finset.univ.filter (fun i => i1 < i ∧ i < i2 ∧