Consider the following rules for signed binary numbers (in two's complement format) [4 points: (SB - signed binary) (s sign bit, 0 for positive and SB SBN BN BD BN BID BD 1 for negative) (BN binary number) (BD binary digit) Give an attribute grammar of the rules (without modifying the BNF rules) to display the decimal value of the signed binary number as the synthesized attribute dv. For example, for SB-0111, SB.dv 7, and for SB-1010, SB.dv 6 a)