Euler := proc(  f :: operator,  # RHS
                a :: numeric,   # left end point
                b :: numeric,   # right end point
               x0 :: numeric,   # initial value
                n :: integer    # number of nods
                             )
   local t, x, h, k;

   h := evalf( (b-a)/(n-1) );
   t := Vector(n);
   for k from 1 to n do
      t[k] := evalf(a + (k-1)*h);
   end do;

   x := Vector(n);
   x[1] := x0;
   for k from 1 to n-1 do
      x[k+1] := evalf(x[k] + h*f(t[k],x[k]));
   end do;

   return t, x;
end proc;