f:Extension value[x]: minimum cardinality of 'value[x]' is 1 f:Extension/f:value[x] 1 value: minimum cardinality of 'value' is 1 comparator: maximum cardinality of 'comparator' is 0 unit: minimum cardinality of 'unit' is 1 system: maximum cardinality of 'system' is 0 code: maximum cardinality of 'code' is 0