BNF Grammar Derivation

Question

I want to apply rules of BNF Grammar to produce derivation for : a_Num

Answer 1

Your question is a bit vague. But below is a BNF (ish) grammar for an integer number.

nz_digit   = '1' | ... | '9';
digit      = '0' | nz_digit;
digitseq   = digit | digitseq, digit;

num        =  '0' | nz_digit, digitseq;