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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def relax_core(self):
 """ Relax and bound the core. After unsatisfiable core splitting, this method is called. If the core contains only one clause, i.e. this clause cannot be satisfied together with the hard clauses of the formula, the formula gets augmented with the negation of the clause (see :func:`remove_unit_core`). Otherwise (if the core contains more than one clause), every clause :math:`c` of the core is *relaxed*. This means a new *relaxation literal* is added to the clause, i.e. :math:`c\gets c\\vee r`, where :math:`r` is a fresh (unused) relaxation variable. After the clauses get relaxed, a new cardinality encoding is added to the formula enforcing the sum of the new relaxation variables to be not greater than 1, :math:`\sum_{c\in\phi}{r\leq 1}`, where :math:`\phi` denotes the unsatisfiable core. """


        if len(self.core) > 1:
            # relaxing
            rels = []

            for clid in self.core:
                self.topv += 1
                rels.append(self.topv)
                self.soft[clid].append(self.topv)

            # creating a new cardinality constraint
            am1 = CardEnc.atmost(lits=rels, top_id=self.topv, encoding=self.cenc)

            for cl in am1.clauses:
                self.hard.append(cl)

            # only if minicard
            # (for other solvers am1.atmosts should be empty)
            for am in am1.atmosts:
                self.atm1.append(am)

            self.topv = am1.nv

        elif len(self.core) == 1:  # unit core => simply negate the clause
            self.remove_unit_core()