Methods to interpret Boolean expressions. Source: 11.js, line 619 Methods and() [ 'and' a b ] returns Boolean. Source: 11.js, line 636 bool() [ 'bool' value ] returns Boolean. Source: 11.js, line 659 not() [ 'not' b ] returns Boolean. Source: 11.js, line 649 or() [ 'or' a b ] returns Boolean. Source: 11.js, line 623