When pattern facets are available in the schema datatype, Boolean datatype
representation is able to distinguish values not only arithmetically (0 or 1)
but also between lexical variances ("0", "1", "false" and "true"), and values
typed as Boolean are represented as n-bit unsigned integer (7.1.9 n-bit
Unsigned Integer), where n is two (2) and the value zero (0), one (1), two
(2) and three (3) each represents value "false", "0", "true" and "1".