Let A $=\{0,1,2,3,4,5,6,7,8,9,,.\}$ be the alphabet. The

grammar is defined as follows:

F $=-$ FN $|$ FN

FN $=$ N $|$ N $.$ N

N $=$ D $|$ D$,$ N

D $=0|1|2|3|4|5|6|7|$

$8|9$