text: r"""
  A subset of sage.categories.all with just the basic categories needed
  for sage startup (i.e. to define ZZ, QQ, ...).
  """
  #*****************************************************************************
  #  Copyright (C) 2008-2009 Nicolas M. Thiery <nthiery at users.sf.net>
  #
  #  Distributed under the terms of the GNU General Public License (GPL)
  #                  http://www.gnu.org/licenses/
  #******************************************************************************
  
  from objects import Objects
  from sets_cat import Sets, EmptySetError
  from posets import Posets
  # For backward compatibility; will be deprecated at some point
  PartiallyOrderedSets = Posets
  OrderedSets = Posets
  
  from additive_magmas import AdditiveMagmas
  from commutative_additive_semigroups import CommutativeAdditiveSemigroups
  from commutative_additive_monoids import CommutativeAdditiveMonoids
  from commutative_additive_groups import CommutativeAdditiveGroups
  
  from magmas import Magmas
  from semigroups import Semigroups
  from monoids import Monoids
  from groups import Groups
  from partially_ordered_monoids import PartiallyOrderedMonoids
  # For backward compatibility; might be deprecated at some point
  OrderedMonoids = PartiallyOrderedMonoids
  
  from rngs import Rngs
  from semirings import Semirings
  from rings import Rings
  from domains import Domains
  from division_rings import DivisionRings
  
  from commutative_rings import CommutativeRings
  from integral_domains import IntegralDomains
  from gcd_domains import GcdDomains
  from principal_ideal_domains import PrincipalIdealDomains
  from euclidean_domains import EuclideanDomains
  from unique_factorization_domains import UniqueFactorizationDomains
  from complete_discrete_valuation import CompleteDiscreteValuationRings
  
  from fields import Fields
  from quotient_fields import QuotientFields
  from finite_fields import FiniteFields
  from discrete_valuation import DiscreteValuationRings, DiscreteValuationFields
  from complete_discrete_valuation import CompleteDiscreteValuationRings, CompleteDiscreteValuationFields
  