code: def convex_conj(self):
          
          return IndicatorNuclearNormUnitBall(
              self.domain,
              conj_exponent(self.outernorm.exponent),
              conj_exponent(self.pwisenorm.exponent))
docs: Convex conjugate of the nuclear norm.
  
          The convex conjugate is the indicator function on the unit ball of
          the dual norm where the dual norm is obtained by taking the conjugate
          exponent of both the outer and singular vector exponents.