reserve x for set;
reserve a, b, c, d, e for Real;
reserve m, n, m1, m2 for Nat;
reserve k, l for Integer;
reserve p for Rational;

theorem
  n>=1 implies n-root 1 = 1
proof
  assume
A1: n>=1;
  hence n-root 1 = n -Root 1 by Def1
    .= 1 by A1,PREPOWER:20;
end;
