A construct (such as a Codd table) is said to be a "strong representation" system (of missing information) if any answer to a query made on the construct can be particularized to obtain an answer for "any" corresponding query on the relations it represents, which are seen as models of the construct. More precisely, if formula_2 is a query formula in the relational algebra (of "pure" relations) and if formula_3 is its lifting to a construct intended to represent missing information, a strong representation has the property that for any query "q" and (table) construct "T", formula_3 lifts "all" the answers to the construct, i.e.: