Natural numbers only include zero if you define it so in the beginning of your book/paper/whatever. Otherwise it’s ambiguous and you should be ashamed of yourself.
Fair enough, as a computer scientist I got tought to use the Neumann definition, which includes zero, unless stated differently by the author. But for general mathematics, I guess it’s used both ways.
Natural numbers only include zero if you define it so in the beginning of your book/paper/whatever. Otherwise it’s ambiguous and you should be ashamed of yourself.
Fair enough, as a computer scientist I got tought to use the Neumann definition, which includes zero, unless stated differently by the author. But for general mathematics, I guess it’s used both ways.