def _multi_variate(base_ring,
num_gens=None,
names=None,
order='negdeglex',
default_prec=None,
sparse=False):
"""
Construct multivariate power series ring.
"""
if names is None:
raise TypeError("you must specify a variable name or names")
if num_gens is None:
if isinstance(names, str):
num_gens = len(names.split(','))
elif isinstance(names, (list, tuple)):
num_gens = len(names)
else:
raise TypeError("variable names must be a string, tuple or list")
names = normalize_names(num_gens, names)
num_gens = len(names)
if default_prec is None:
default_prec = 12
if base_ring not in commutative_rings.CommutativeRings():
raise TypeError("base_ring must be a commutative ring")
from sage.rings.multi_power_series_ring import MPowerSeriesRing_generic
R = MPowerSeriesRing_generic(base_ring,
num_gens,
names,
order=order,
default_prec=default_prec,
sparse=sparse)
return R
import laurent_series_ring_element
import commutative_ring
import integral_domain
import integer
from infinity import infinity
import sage.misc.latex as latex
from sage.structure.nonexact import Nonexact
from sage.interfaces.magma import MagmaElement
from sage.rings.fraction_field_element import FractionFieldElement
from sage.misc.sage_eval import sage_eval
from sage.structure.unique_representation import UniqueRepresentation
from sage.structure.category_object import normalize_names
import sage.categories.commutative_rings as commutative_rings
_CommutativeRings = commutative_rings.CommutativeRings()
import sage.categories.integral_domains as integral_domains
_IntegralDomains = integral_domains.IntegralDomains()
import sage.categories.fields as fields
_Fields = fields.Fields()
from sage.categories.complete_discrete_valuation import CompleteDiscreteValuationRings
def PowerSeriesRing(base_ring,
name=None,
arg2=None,
names=None,
sparse=False,
default_prec=None,
order='negdeglex',
