In the
OrQuery
eval
function what would happen if itsrhs
member returned an empty set? What if itslhs
member did so? What if bothrhs
andlhs
returned empty sets?
If its rhs
member returned an empty set, then the insert
function would insert no element into the ret_lines
.
If its lhs
member returned an empty set, then the ret_lines
would be initialized as an empty set.
If both rhs
and lhs
returned empty sets, then the ret_lines
would also be an empty set.