Base 16 Representation and
4-bit Pattern Names

The name of the binary pattern 1010 is "A". The hex digit that corresponds to the number represented by 1010₂ is also "A".

It is OK to have a pattern that has the name "A" and also to use "A" as a digit.

When a 4-bit pattern represents a number in base two, that number represented in hex is the same digit as the bit pattern name.

0  is a digit, 
   representing 
   zero. 
.
.
.
A  is a digit, 
   representing  
   ten. 
.
.
.
F  is a digit, 
   representing  
   fifteen. 

0  is the name 
   of the pattern 
   0000
.
.
.
A  is the name 
   of the pattern 
   1010
.
.
.
F  is the name 
   of the pattern 
   1111

0  in 4-bit 
   binary is 
   0000 
.
.
.
A  in 4-bit 
   binary is 
   1010
.
.
.
F  in 4-bit 
   binary is 
   1111

The name of a 4-bit pattern (regarded as an abstract pattern) is the same as the hexadecimal digit whose representation in binary is that 4-bit pattern. This is not accidental.