(defun tt (num n / b dim r sl)
(setq dim(getvar "DIMZIN"))
(setvar "DIMZIN" 0)
(setq
b(rtos num 2 (1+ n))
sl(strlen b)
)
(setq r(atof (rtos num 2 n)))
(if (>(- num(atof b))0.)
r
(if (and
(=(substr b sl 1)"5")
(=(rem(ascii(substr b (1- sl)1))2)0)
)
(setq r(-(atof (rtos num 2 n))(expt 10. (- n))))
r
)
)
(setvar "DIMZIN" 0)
r
)