> For those who now what it means, o.999... = 1 is a > trivial fsct and easy to prove! > 0.999... is NOT a real number. It is a symbol that represents an > infinite series.
Using standard definitions, 0.999... does not represent an infinite series, it is a symbol that represents a real number. One way to define which real number is to use the sum of an infinite series, but there are other, equivalent ways (e.g. the real number represented by the equivalence class of Cauchy sequences to which (0.9,0.99,0.999, ...) belongs). You can use the concepts of limit and convergence but you do not need them.