Update notes.md

notes.md

@@ -59,7 +59,7 @@ Other than the headlines at the top, additional benefits of (a correct implement
 1. no risk of obstructing AD,
 1. rand_tangent can just use structural tangents, simplifying its implementation and improving its reliability,
 1. we can probably finally make `to_vec` treat things structurally (although we also need to extend it in other ways), which will also deal with reliability / simplicity of implementation problems,
-1. generic constructor for composite types easy to implement,
+1. generic constructor for composite types easy to implement since we can be sure of obtaining a structural tangent, and rid ourselves of the "need to define an adjoint for constructor..." errors we see in Zygote,
 1. due to the utility functionality, all of the examples that I've encountered so far are very concise.
 
 The potential downside is additional conversions between natural and structural tangents. Most of the time, these are free. When they're not, you ideally want to minimise them. I'm not sure how often this is going to be a problem, but it's something we're essentially ignoring at the minute (as far as I know), so we're probably going to have to incur some additional cost at some point even if we don't go down the route proposed here.