This class represents the Concept of individuals being the
events corresponding to the same ULine; it contains, for sake of simplicity,
the corresponding ULine too.
Returns the evaluation of the logical expression [A until B(ind)],
where A is this Concept, B is a given other Concept, ind is the Individual for which
expression has to be evaluated; lastUntil is the given expression value for
the last (previous) Individual with respect to ind.
Return the evaluation of the logical expression [A until B(ind)],
where A is this Concept, B is a given Concept, ind is the Individual for which
expression has to be evaluted.