Symbolic command 'rewrite' changes the domain of a function?

[ViktorKorobov]

I want to replace function (F) with a more compact expression (F2). However, an error occurs.

[ValeryOchkov]

And what we have in Maple or Mathcad 11?

[LucMeekes]

The same as what every mathematical application should do when asked to evaluate the coth of 0: throw a devide by zero error.

Success!
Luc

[ViktorKorobov]

Thank you, Luke. I know it. I want this to know Mathcad Prime (see picture). Maybe it works in Valery's Mathcad Prime Minister?