I interpreted this paragraph as saying that the compiler will report an error on the use of the call operator `x(y, z)` syntax, not that attempting to implement more than one of the traits on a single type was illegal.

In any case, I see value in using distinct names for the methods.  The only reason I could see not to do so would be to ease designing certain macros, if our macros were able to expand into method-items (which I believe they currently cannot).