Template:IsNumber


 * First Parameter: Number to be tested
 * Second Parameter (optional): Test, if number is
 * empty or R: a real number
 * R+: a nonnegative number
 * R-: a nonpositive number
 * Z: an integer
 * N or Z+: a natural number (incl. 0)
 * Z-: a nonpositive integer
 * Third Parameter (optional): Test, if number was rounded