Summary:
* **Both LHS and RHS Fixed-width Priority**
- - Exactly the same as for when RHS is an Integer
+ - Exactly the same as for when RHS is an Integer, given that the
+ integer fixed width is, in fact, an integer.
+* **Either LHS or RHS Elwidth Priority**
+ - It is unsafe (not possible) to respect the fixed width therefore
+ it is always ignored
+ - all operators always expected to work (caveat: by only using
+ the elwidths)
+ - all operators work because they match elwidth-for-elwidth
+ in their computations.
+