Function CrossProduct

fem/coefficient.cpp:4304–4311

  shared_ptr<CoefficientFunction> CrossProduct (shared_ptr<CoefficientFunction> c1,
                                                shared_ptr<CoefficientFunction> c2)
  {
    if (c1->IsZeroCF() || c2->IsZeroCF())
      return ZeroCF( c1->Dimensions() );
    
    return make_shared<CrossProductCoefficientFunction> (c1, c2);
  }

  shared_ptr<CoefficientFunction> UnitVectorCF (int dim, int coord)
  {