Fix comments

src/rrules/blas.jl

@@ -230,7 +230,7 @@ function rrule!!(
     y, dy = viewify(y_dy)
 
     # In this rule we optimise carefully for the special case a == 1 && b == 0, which
-    # corresponds to simply multiplying symm(A) and B together, and writing the result to C.
+    # corresponds to simply multiplying symm(A) and x together, and writing the result to y.
     # This is an extremely common edge case, so it's important to do well for it.
     y_copy = copy(y)
     tmp_ref = Ref{Vector{T}}()
@@ -269,13 +269,13 @@ function rrule!!(
             dA[n] -= α * dA_tmp[n]
         end
 
-        # gradient w.r.t. B.
+        # gradient w.r.t. x.
         BLAS.symv!(ul, α, A, dy, one(T), dx)
 
         # gradient w.r.t. beta.
         dβ = dot(dy, y)
 
-        # gradient w.r.t. C.
+        # gradient w.r.t. y.
         BLAS.scal!(β, dy)
 
         return NoRData(), NoRData(), dα, NoRData(), NoRData(), dβ, NoRData()