2.4.8.8 Sharpsign B

#Brational reads rational in binary (radix 2). For example,

 #B1101 ≡ 13 ;1101_2
 #b101/11 ≡ 5/3

The consequences are undefined if the token immediately following the #B does not have the syntax of a binary (i.e., radix 2) rational.