 reserve n,m,i,p for Nat,
         h,k,r,r1,r2,x,x0,x1,x2,x3 for Real;
 reserve f,f1,f2,g for Function of REAL,REAL;

theorem Th1:
  x0>0 & x1>0 implies
  log(number_e,x0) - log(number_e,x1) = log(number_e,x0/x1)
proof
  assume
A1:x0>0 & x1>0;
  number_e > 1 by TAYLOR_1:11,XXREAL_0:2;
  hence thesis by A1,POWER:54;
end;
