Returns true if the first argument is true and the second is false.
xs:boolean values. Also
         used in the definition of the "le" operator.op:boolean-greater-than( $arg1 as xs:boolean,$arg2 as xs:booleanxs:booleanThe function call op:boolean-greater-than($A, $B) is defined to return the
            same result as op:boolean-less-than($B, $A)