The length (in bits) of the bit string x. For example, |01100100| = 8.
Source(s):
NIST SP 800-106
The absolute value of x.
Source(s):
NIST SP 800-56B Rev. 2
under │x│
The length of a bit string X in bits.
Source(s):
NIST SP 800-108r1
under |X|