Compute square roots. (Slow for large numbers.)

sqrt.rui

r  *7
=0 +3 .  -7 *7 .  .  .  .  .  .  *4 -1 -7 +9 +8  +8  :2
      -8 .  *8 ~  .  .  -0 =1 ~  .  .  -9 w  +10 -7  .  *5  -8   *6  :2
                                    .  :7 
                                                            =100 *7  !
                                                                     =10 *8 !
=7:7
=8:8
=9:9
                                                 .   -0 *11 !
                                                            -8