named.addAll(r1.named().inner());
named.addAll(r2.named().inner());
if (! isInnerJoin) {
r1.overwriteExpand();
r2.overwriteExpand();
}
Proposition p = visitJoinSpecification(joinSpecification, columnNamesLookupForJoin2(r1, r2));
// TODO move the check inside {@link Proposition} instead of matching like this