def test_rebuild():
from sympy.core.add import Add
expr = Basic.__new__(Add, S(1), S(2))
assert rebuild(expr) == 3
def replacement1895(m, n, u, v, x):
a = D(u, x)
b = D(v, x)
return -Simp(u**(m + S(1))*v**(n + S(1))/((m + S(1))*(-a*v + b*u)), x)
def replacement1898(m, n, u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist(n*(-a*v + b*u)/(a*(m + n + S(1))), Int(u**m*v**(n + S(-1)), x), x) + Simp(u**(m + S(1))*v**n/(a*(m + n + S(1))), x)
def replacement1891(n, u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist(a/(-a*v + b*u), Int(v**(n + S(1))/u, x), x) + Simp(v**(n + S(1))/((n + S(1))*(-a*v + b*u)), x)
def replacement1893(u, v, x):
a = D(u, x)
b = D(v, x)
return Simp(S(2)*atanh(sqrt(u)*Rt(a*b, S(2))/(a*sqrt(v)))/Rt(a*b, S(2)), x)
def replacement1887(n, u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist((-a*v + b*u)/a, Int(v**(n + S(-1))/u, x), x) + Simp(v**n/(a*n), x)
def replacement1889(u, v, x):
a = D(u, x)
b = D(v, x)
return Simp(S(2)*ArcTan(sqrt(v)/Rt((-a*v + b*u)/a, S(2)))/(a*Rt((-a*v + b*u)/a, S(2))), x)
def __init__(self, factors=None): # Factors
"""Initialize Factors from dict or expr.
Examples
========
>>> from sympy.core.exprtools import Factors
>>> from sympy.abc import x
>>> from sympy import I
>>> e = 2*x**3
>>> Factors(e)
Factors({2: 1, x: 3})
>>> Factors(e.as_powers_dict())
Factors({2: 1, x: 3})
>>> f = _
>>> f.factors # underlying dictionary
{2: 1, x: 3}
>>> f.gens # base of each factor
frozenset([2, x])
>>> Factors(0)
Factors({0: 1})
>>> Factors(I)
Factors({I: 1})
Notes
=====
Although a dictionary can be passed, only minimal checking is
performed: powers of -1 and I are made canonical.
"""
if isinstance(factors, (SYMPY_INTS, float)):
factors = S(factors)
if isinstance(factors, Factors):
factors = factors.factors.copy()
elif factors is None or factors is S.One:
factors = {}
elif factors is S.Zero or factors == 0:
factors = {S.Zero: S.One}
elif isinstance(factors, Number):
n = factors
factors = {}
if n < 0:
factors[S.NegativeOne] = S.One
n = -n
if n is not S.One:
if n.is_Float or n.is_Integer or n is S.Infinity:
factors[n] = S.One
elif n.is_Rational:
# since we're processing Numbers, the denominator is
# stored with a negative exponent; all other factors
# are left .
if n.p != 1:
factors[Integer(n.p)] = S.One
factors[Integer(n.q)] = S.NegativeOne
else:
raise ValueError(
'Expected Float|Rational|Integer, not %s' % n)
elif isinstance(factors, Basic) and not factors.args:
factors = {factors: S.One}
elif isinstance(factors, Expr):
c, nc = factors.args_cnc()
i = c.count(I)
for _ in range(i):
c.remove(I)
factors = dict(Mul._from_args(c).as_powers_dict())
if i:
factors[I] = S.One * i
if nc:
factors[Mul(*nc, evaluate=False)] = S.One
else:
factors = factors.copy() # /!\ should be dict-like
# tidy up -/+1 and I exponents if Rational
handle = []
for k in factors:
if k is I or k in (-1, 1):
handle.append(k)
if handle:
i1 = S.One
for k in handle:
if not _isnumber(factors[k]):
continue
i1 *= k**factors.pop(k)
if i1 is not S.One:
for a in i1.args if i1.is_Mul else [
i1
]: # at worst, -1.0*I*(-1)**e
if a is S.NegativeOne:
factors[a] = S.One
elif a is I:
factors[I] = S.One
elif a.is_Pow:
if S.NegativeOne not in factors:
factors[S.NegativeOne] = S.Zero
factors[S.NegativeOne] += a.exp
elif a == 1:
factors[a] = S.One
elif a == -1:
factors[-a] = S.One
factors[S.NegativeOne] = S.One
else:
raise ValueError('unexpected factor in i1: %s' % a)
self.factors = factors
try:
self.gens = frozenset(factors.keys())
except AttributeError:
raise TypeError('expecting Expr or dictionary')
def _monotonic_sign(self):
"""Return the value closest to 0 that ``self`` may have if all symbols
are signed and the result is uniformly the same sign for all values of symbols.
If a symbol is only signed but not known to be an
integer or the result is 0 then a symbol representative of the sign of self
will be returned. Otherwise, None is returned if a) the sign could be positive
or negative or b) self is not in one of the following forms:
- L(x, y, ...) + A: a function linear in all symbols x, y, ... with an
additive constant; if A is zero then the function can be a monomial whose
sign is monotonic over the range of the variables, e.g. (x + 1)**3 if x is
nonnegative.
- A/L(x, y, ...) + B: the inverse of a function linear in all symbols x, y, ...
that does not have a sign change from positive to negative for any set
of values for the variables.
- M(x, y, ...) + A: a monomial M whose factors are all signed and a constant, A.
- A/M(x, y, ...) + B: the inverse of a monomial and constants A and B.
- P(x): a univariate polynomial
Examples
========
>>> from sympy.core.exprtools import _monotonic_sign as F
>>> from sympy import Dummy, S
>>> nn = Dummy(integer=True, nonnegative=True)
>>> p = Dummy(integer=True, positive=True)
>>> p2 = Dummy(integer=True, positive=True)
>>> F(nn + 1)
1
>>> F(p - 1)
_nneg
>>> F(nn*p + 1)
1
>>> F(p2*p + 1)
2
>>> F(nn - 1) # could be negative, zero or positive
"""
if not self.is_real:
return
if (-self).is_Symbol:
rv = _monotonic_sign(-self)
return rv if rv is None else -rv
if not self.is_Add and self.as_numer_denom()[1].is_number:
s = self
if s.is_prime:
if s.is_odd:
return S(3)
else:
return S(2)
elif s.is_positive:
if s.is_even:
return S(2)
elif s.is_integer:
return S.One
else:
return _eps
elif s.is_negative:
if s.is_even:
return S(-2)
elif s.is_integer:
return S.NegativeOne
else:
return -_eps
if s.is_zero or s.is_nonpositive or s.is_nonnegative:
return S.Zero
return None
# univariate polynomial
free = self.free_symbols
if len(free) == 1:
if self.is_polynomial():
from sympy.polys.polytools import real_roots
from sympy.polys.polyroots import roots
from sympy.polys.polyerrors import PolynomialError
x = free.pop()
x0 = _monotonic_sign(x)
if x0 == _eps or x0 == -_eps:
x0 = S.Zero
if x0 is not None:
d = self.diff(x)
if d.is_number:
roots = []
else:
try:
roots = real_roots(d)
except (PolynomialError, NotImplementedError):
roots = [r for r in roots(d, x) if r.is_real]
y = self.subs(x, x0)
if x.is_nonnegative and all(r <= x0 for r in roots):
if y.is_nonnegative and d.is_positive:
if y:
return y if y.is_positive else Dummy('pos',
positive=True)
else:
return Dummy('nneg', nonnegative=True)
if y.is_nonpositive and d.is_negative:
if y:
return y if y.is_negative else Dummy('neg',
negative=True)
else:
return Dummy('npos', nonpositive=True)
elif x.is_nonpositive and all(r >= x0 for r in roots):
if y.is_nonnegative and d.is_negative:
if y:
return Dummy('pos', positive=True)
else:
return Dummy('nneg', nonnegative=True)
if y.is_nonpositive and d.is_positive:
if y:
return Dummy('neg', negative=True)
else:
return Dummy('npos', nonpositive=True)
else:
n, d = self.as_numer_denom()
den = None
if n.is_number:
den = _monotonic_sign(d)
elif not d.is_number:
if _monotonic_sign(n) is not None:
den = _monotonic_sign(d)
if den is not None and (den.is_positive or den.is_negative):
v = n * den
if v.is_positive:
return Dummy('pos', positive=True)
elif v.is_nonnegative:
return Dummy('nneg', nonnegative=True)
elif v.is_negative:
return Dummy('neg', negative=True)
elif v.is_nonpositive:
return Dummy('npos', nonpositive=True)
return None
# multivariate
c, a = self.as_coeff_Add()
v = None
if not a.is_polynomial():
# F/A or A/F where A is a number and F is a signed, rational monomial
n, d = a.as_numer_denom()
if not (n.is_number or d.is_number):
return
if (
a.is_Mul or a.is_Pow) and \
a.is_rational and \
all(p.exp.is_Integer for p in a.atoms(Pow) if p.is_Pow) and \
(a.is_positive or a.is_negative):
v = S(1)
for ai in Mul.make_args(a):
if ai.is_number:
v *= ai
continue
reps = {}
for x in ai.free_symbols:
reps[x] = _monotonic_sign(x)
if reps[x] is None:
return
v *= ai.subs(reps)
elif c:
# signed linear expression
if not any(p for p in a.atoms(Pow) if not p.is_number) and (
a.is_nonpositive or a.is_nonnegative):
free = list(a.free_symbols)
p = {}
for i in free:
v = _monotonic_sign(i)
if v is None:
return
p[i] = v or (_eps if i.is_nonnegative else -_eps)
v = a.xreplace(p)
if v is not None:
rv = v + c
if v.is_nonnegative and rv.is_positive:
return rv.subs(_eps, 0)
if v.is_nonpositive and rv.is_negative:
return rv.subs(_eps, 0)
def test_issue_20913():
assert Poly(x + 9671406556917067856609794,
x).real_roots() == [-9671406556917067856609794]
assert Poly(x**3 + 4, x).real_roots() == [-2**(S(2) / 3)]
def is_convergent(self):
r"""Checks for the convergence of a Sum.
We divide the study of convergence of infinite sums and products in
two parts.
First Part:
One part is the question whether all the terms are well defined, i.e.,
they are finite in a sum and also non-zero in a product. Zero
is the analogy of (minus) infinity in products as :math:`e^{-\infty} = 0`.
Second Part:
The second part is the question of convergence after infinities,
and zeros in products, have been omitted assuming that their number
is finite. This means that we only consider the tail of the sum or
product, starting from some point after which all terms are well
defined.
For example, in a sum of the form:
.. math::
\sum_{1 \leq i < \infty} \frac{1}{n^2 + an + b}
where a and b are numbers. The routine will return true, even if there
are infinities in the term sequence (at most two). An analogous
product would be:
.. math::
\prod_{1 \leq i < \infty} e^{\frac{1}{n^2 + an + b}}
This is how convergence is interpreted. It is concerned with what
happens at the limit. Finding the bad terms is another independent
matter.
Note: It is responsibility of user to see that the sum or product
is well defined.
There are various tests employed to check the convergence like
divergence test, root test, integral test, alternating series test,
comparison tests, Dirichlet tests. It returns true if Sum is convergent
and false if divergent and NotImplementedError if it can not be checked.
References
==========
.. [1] https://en.wikipedia.org/wiki/Convergence_tests
Examples
========
>>> from sympy import factorial, S, Sum, Symbol, oo
>>> n = Symbol('n', integer=True)
>>> Sum(n/(n - 1), (n, 4, 7)).is_convergent()
True
>>> Sum(n/(2*n + 1), (n, 1, oo)).is_convergent()
False
>>> Sum(factorial(n)/5**n, (n, 1, oo)).is_convergent()
False
>>> Sum(1/n**(S(6)/5), (n, 1, oo)).is_convergent()
True
See Also
========
Sum.is_absolutely_convergent()
Product.is_convergent()
"""
from sympy import Interval, Integral, Limit, log, symbols, Ge, Gt, simplify
p, q = symbols('p q', cls=Wild)
sym = self.limits[0][0]
lower_limit = self.limits[0][1]
upper_limit = self.limits[0][2]
sequence_term = self.function
if len(sequence_term.free_symbols) > 1:
raise NotImplementedError(
"convergence checking for more than one symbol "
"containing series is not handled")
if lower_limit.is_finite and upper_limit.is_finite:
return S.true
# transform sym -> -sym and swap the upper_limit = S.Infinity
# and lower_limit = - upper_limit
if lower_limit is S.NegativeInfinity:
if upper_limit is S.Infinity:
return Sum(sequence_term, (sym, 0, S.Infinity)).is_convergent() and \
Sum(sequence_term, (sym, S.NegativeInfinity, 0)).is_convergent()
sequence_term = simplify(sequence_term.xreplace({sym: -sym}))
lower_limit = -upper_limit
upper_limit = S.Infinity
interval = Interval(lower_limit, upper_limit)
# Piecewise function handle
if sequence_term.is_Piecewise:
for func_cond in sequence_term.args:
if func_cond[1].func is Ge or func_cond[
1].func is Gt or func_cond[1] == True:
return Sum(
func_cond[0],
(sym, lower_limit, upper_limit)).is_convergent()
return S.true
### -------- Divergence test ----------- ###
try:
lim_val = limit(sequence_term, sym, upper_limit)
if lim_val.is_number and lim_val is not S.Zero:
return S.false
except NotImplementedError:
pass
try:
lim_val_abs = limit(abs(sequence_term), sym, upper_limit)
if lim_val_abs.is_number and lim_val_abs is not S.Zero:
return S.false
except NotImplementedError:
pass
order = O(sequence_term, (sym, S.Infinity))
### --------- p-series test (1/n**p) ---------- ###
p1_series_test = order.expr.match(sym**p)
if p1_series_test is not None:
if p1_series_test[p] < -1:
return S.true
if p1_series_test[p] > -1:
return S.false
p2_series_test = order.expr.match((1 / sym)**p)
if p2_series_test is not None:
if p2_series_test[p] > 1:
return S.true
if p2_series_test[p] < 1:
return S.false
### ----------- root test ---------------- ###
lim = Limit(abs(sequence_term)**(1 / sym), sym, S.Infinity)
lim_evaluated = lim.doit()
if lim_evaluated.is_number:
if lim_evaluated < 1:
return S.true
if lim_evaluated > 1:
return S.false
### ------------- alternating series test ----------- ###
dict_val = sequence_term.match((-1)**(sym + p) * q)
if not dict_val[p].has(sym) and is_decreasing(dict_val[q], interval):
return S.true
### ------------- comparison test ------------- ###
# (1/log(n)**p) comparison
log_test = order.expr.match(1 / (log(sym)**p))
if log_test is not None:
return S.false
# (1/(n*log(n)**p)) comparison
log_n_test = order.expr.match(1 / (sym * (log(sym))**p))
if log_n_test is not None:
if log_n_test[p] > 1:
return S.true
return S.false
# (1/(n*log(n)*log(log(n))*p)) comparison
log_log_n_test = order.expr.match(1 / (sym *
(log(sym) * log(log(sym))**p)))
if log_log_n_test is not None:
if log_log_n_test[p] > 1:
return S.true
return S.false
# (1/(n**p*log(n))) comparison
n_log_test = order.expr.match(1 / (sym**p * log(sym)))
if n_log_test is not None:
if n_log_test[p] > 1:
return S.true
return S.false
### ------------- integral test -------------- ###
if is_decreasing(sequence_term, interval):
integral_val = Integral(sequence_term,
(sym, lower_limit, upper_limit))
try:
integral_val_evaluated = integral_val.doit()
if integral_val_evaluated.is_number:
return S(integral_val_evaluated.is_finite)
except NotImplementedError:
pass
### -------------- Dirichlet tests -------------- ###
if order.expr.is_Mul:
a_n, b_n = order.expr.args[0], order.expr.args[1]
m = Dummy('m', integer=True)
def _dirichlet_test(g_n):
try:
ing_val = limit(
Sum(g_n, (sym, interval.inf, m)).doit(), m, S.Infinity)
if ing_val.is_finite:
return S.true
except NotImplementedError:
pass
if is_decreasing(a_n, interval):
dirich1 = _dirichlet_test(b_n)
if dirich1 is not None:
return dirich1
if is_decreasing(b_n, interval):
dirich2 = _dirichlet_test(a_n)
if dirich2 is not None:
return dirich2
raise NotImplementedError(
"The algorithm to find the Sum convergence of %s "
"is not yet implemented" % (sequence_term))
def test_roots0():
assert roots(1, x) == {}
assert roots(x, x) == {S.Zero: 1}
assert roots(x**9, x) == {S.Zero: 9}
assert roots(((x - 2) * (x + 3) * (x - 4)).expand(), x) == {
-S(3): 1,
S(2): 1,
S(4): 1
}
assert roots(2 * x + 1, x) == {Rational(-1, 2): 1}
assert roots((2 * x + 1)**2, x) == {Rational(-1, 2): 2}
assert roots((2 * x + 1)**5, x) == {Rational(-1, 2): 5}
assert roots((2 * x + 1)**10, x) == {Rational(-1, 2): 10}
assert roots(x**4 - 1, x) == {I: 1, S.One: 1, -S.One: 1, -I: 1}
assert roots((x**4 - 1)**2, x) == {I: 2, S.One: 2, -S.One: 2, -I: 2}
assert roots(((2 * x - 3)**2).expand(), x) == {Rational(3, 2): 2}
assert roots(((2 * x + 3)**2).expand(), x) == {Rational(-3, 2): 2}
assert roots(((2 * x - 3)**3).expand(), x) == {Rational(3, 2): 3}
assert roots(((2 * x + 3)**3).expand(), x) == {Rational(-3, 2): 3}
assert roots(((2 * x - 3)**5).expand(), x) == {Rational(3, 2): 5}
assert roots(((2 * x + 3)**5).expand(), x) == {Rational(-3, 2): 5}
assert roots(((a * x - b)**5).expand(), x) == {b / a: 5}
assert roots(((a * x + b)**5).expand(), x) == {-b / a: 5}
assert roots(x**2 + (-a - 1) * x + a, x) == {a: 1, S.One: 1}
assert roots(x**4 - 2 * x**2 + 1, x) == {S.One: 2, S.NegativeOne: 2}
assert roots(x**6 - 4*x**4 + 4*x**3 - x**2, x) == \
{S.One: 2, -1 - sqrt(2): 1, S.Zero: 2, -1 + sqrt(2): 1}
assert roots(x**8 - 1, x) == {
sqrt(2) / 2 + I * sqrt(2) / 2: 1,
sqrt(2) / 2 - I * sqrt(2) / 2: 1,
-sqrt(2) / 2 + I * sqrt(2) / 2: 1,
-sqrt(2) / 2 - I * sqrt(2) / 2: 1,
S.One: 1,
-S.One: 1,
I: 1,
-I: 1
}
f = -2016*x**2 - 5616*x**3 - 2056*x**4 + 3324*x**5 + 2176*x**6 - \
224*x**7 - 384*x**8 - 64*x**9
assert roots(f) == {
S.Zero: 2,
-S(2): 2,
S(2): 1,
Rational(-7, 2): 1,
Rational(-3, 2): 1,
Rational(-1, 2): 1,
Rational(3, 2): 1
}
assert roots((a + b + c) * x - (a + b + c + d), x) == {
(a + b + c + d) / (a + b + c): 1
}
assert roots(x**3 + x**2 - x + 1, x, cubics=False) == {}
assert roots(((x - 2) * (x + 3) * (x - 4)).expand(), x, cubics=False) == {
-S(3): 1,
S(2): 1,
S(4): 1
}
assert roots(((x - 2)*(x + 3)*(x - 4)*(x - 5)).expand(), x, cubics=False) == \
{-S(3): 1, S(2): 1, S(4): 1, S(5): 1}
assert roots(x**3 + 2 * x**2 + 4 * x + 8, x) == {
-S(2): 1,
-2 * I: 1,
2 * I: 1
}
assert roots(x**3 + 2*x**2 + 4*x + 8, x, cubics=True) == \
{-2*I: 1, 2*I: 1, -S(2): 1}
assert roots((x**2 - x)*(x**3 + 2*x**2 + 4*x + 8), x ) == \
{S.One: 1, S.Zero: 1, -S(2): 1, -2*I: 1, 2*I: 1}
r1_2, r1_3 = S.Half, Rational(1, 3)
x0 = (3 * sqrt(33) + 19)**r1_3
x1 = 4 / x0 / 3
x2 = x0 / 3
x3 = sqrt(3) * I / 2
x4 = x3 - r1_2
x5 = -x3 - r1_2
assert roots(x**3 + x**2 - x + 1, x, cubics=True) == {
-x1 - x2 - r1_3: 1,
-x1 / x4 - x2 * x4 - r1_3: 1,
-x1 / x5 - x2 * x5 - r1_3: 1,
}
f = (x**2 + 2 * x + 3).subs(x, 2 * x**2 + 3 * x).subs(x, 5 * x - 4)
r13_20, r1_20 = [Rational(*r) for r in ((13, 20), (1, 20))]
s2 = sqrt(2)
assert roots(f, x) == {
r13_20 + r1_20 * sqrt(1 - 8 * I * s2): 1,
r13_20 - r1_20 * sqrt(1 - 8 * I * s2): 1,
r13_20 + r1_20 * sqrt(1 + 8 * I * s2): 1,
r13_20 - r1_20 * sqrt(1 + 8 * I * s2): 1,
}
f = x**4 + x**3 + x**2 + x + 1
r1_4, r1_8, r5_8 = [Rational(*r) for r in ((1, 4), (1, 8), (5, 8))]
assert roots(f, x) == {
-r1_4 + r1_4 * 5**r1_2 + I * (r5_8 + r1_8 * 5**r1_2)**r1_2: 1,
-r1_4 + r1_4 * 5**r1_2 - I * (r5_8 + r1_8 * 5**r1_2)**r1_2: 1,
-r1_4 - r1_4 * 5**r1_2 + I * (r5_8 - r1_8 * 5**r1_2)**r1_2: 1,
-r1_4 - r1_4 * 5**r1_2 - I * (r5_8 - r1_8 * 5**r1_2)**r1_2: 1,
}
f = z**3 + (-2 - y) * z**2 + (1 + 2 * y - 2 * x**2) * z - y + 2 * x**2
assert roots(f, z) == {
S.One: 1,
S.Half + S.Half * y + S.Half * sqrt(1 - 2 * y + y**2 + 8 * x**2): 1,
S.Half + S.Half * y - S.Half * sqrt(1 - 2 * y + y**2 + 8 * x**2): 1,
}
assert roots(a * b * c * x**3 + 2 * x**2 + 4 * x + 8, x,
cubics=False) == {}
assert roots(a * b * c * x**3 + 2 * x**2 + 4 * x + 8, x, cubics=True) != {}
assert roots(x**4 - 1, x, filter='Z') == {S.One: 1, -S.One: 1}
assert roots(x**4 - 1, x, filter='I') == {I: 1, -I: 1}
assert roots((x - 1) * (x + 1), x) == {S.One: 1, -S.One: 1}
assert roots((x - 1) * (x + 1), x, predicate=lambda r: r.is_positive) == {
S.One: 1
}
assert roots(x**4 - 1, x, filter='Z', multiple=True) == [-S.One, S.One]
assert roots(x**4 - 1, x, filter='I', multiple=True) == [I, -I]
ar, br = symbols('a, b', real=True)
p = x**2 * (ar - br)**2 + 2 * x * (br - ar) + 1
assert roots(p, x, filter='R') == {1 / (ar - br): 2}
assert roots(x**3, x, multiple=True) == [S.Zero, S.Zero, S.Zero]
assert roots(1234, x, multiple=True) == []
f = x**6 - x**5 + x**4 - x**3 + x**2 - x + 1
assert roots(f) == {
-I * sin(pi / 7) + cos(pi / 7): 1,
-I * sin(pi * Rational(2, 7)) - cos(pi * Rational(2, 7)): 1,
-I * sin(pi * Rational(3, 7)) + cos(pi * Rational(3, 7)): 1,
I * sin(pi / 7) + cos(pi / 7): 1,
I * sin(pi * Rational(2, 7)) - cos(pi * Rational(2, 7)): 1,
I * sin(pi * Rational(3, 7)) + cos(pi * Rational(3, 7)): 1,
}
g = ((x**2 + 1) * f**2).expand()
assert roots(g) == {
-I * sin(pi / 7) + cos(pi / 7): 2,
-I * sin(pi * Rational(2, 7)) - cos(pi * Rational(2, 7)): 2,
-I * sin(pi * Rational(3, 7)) + cos(pi * Rational(3, 7)): 2,
I * sin(pi / 7) + cos(pi / 7): 2,
I * sin(pi * Rational(2, 7)) - cos(pi * Rational(2, 7)): 2,
I * sin(pi * Rational(3, 7)) + cos(pi * Rational(3, 7)): 2,
-I: 1,
I: 1,
}
r = roots(x**3 + 40 * x + 64)
real_root = [rx for rx in r if rx.is_real][0]
cr = 108 + 6 * sqrt(1074)
assert real_root == -2 * root(cr, 3) / 3 + 20 / root(cr, 3)
eq = Poly((7 + 5 * sqrt(2)) * x**3 + (-6 - 4 * sqrt(2)) * x**2 +
(-sqrt(2) - 1) * x + 2,
x,
domain='EX')
assert roots(eq) == {-1 + sqrt(2): 1, -2 + 2 * sqrt(2): 1, -sqrt(2) + 1: 1}
eq = Poly(41 * x**5 + 29 * sqrt(2) * x**5 - 153 * x**4 -
108 * sqrt(2) * x**4 + 175 * x**3 + 125 * sqrt(2) * x**3 -
45 * x**2 - 30 * sqrt(2) * x**2 - 26 * sqrt(2) * x - 26 * x + 24,
x,
domain='EX')
assert roots(eq) == {
-sqrt(2) + 1: 1,
-2 + 2 * sqrt(2): 1,
-1 + sqrt(2): 1,
-4 + 4 * sqrt(2): 1,
-3 + 3 * sqrt(2): 1
}
eq = Poly(x**3 - 2 * x**2 + 6 * sqrt(2) * x**2 - 8 * sqrt(2) * x + 23 * x -
14 + 14 * sqrt(2),
x,
domain='EX')
assert roots(eq) == {
-2 * sqrt(2) + 2: 1,
-2 * sqrt(2) + 1: 1,
-2 * sqrt(2) - 1: 1
}
assert roots(Poly((x + sqrt(2))**3 - 7, x, domain='EX')) == \
{-sqrt(2) + root(7, 3)*(-S.Half - sqrt(3)*I/2): 1,
-sqrt(2) + root(7, 3)*(-S.Half + sqrt(3)*I/2): 1,
-sqrt(2) + root(7, 3): 1}
def test_eval_approx_relative():
CRootOf.clear_cache()
t = [CRootOf(x**3 + 10 * x + 1, i) for i in range(3)]
assert [i.eval_rational(1e-1) for i in t] == [
Rational(-21, 220),
Rational(15, 256) - I * 805 / 256,
Rational(15, 256) + I * 805 / 256
]
t[0]._reset()
assert [i.eval_rational(1e-1, 1e-4) for i in t] == [
Rational(-21, 220),
Rational(3275, 65536) - I * 414645 / 131072,
Rational(3275, 65536) + I * 414645 / 131072
]
assert S(t[0]._get_interval().dx) < 1e-1
assert S(t[1]._get_interval().dx) < 1e-1
assert S(t[1]._get_interval().dy) < 1e-4
assert S(t[2]._get_interval().dx) < 1e-1
assert S(t[2]._get_interval().dy) < 1e-4
t[0]._reset()
assert [i.eval_rational(1e-4, 1e-4) for i in t] == [
Rational(-2001, 20020),
Rational(6545, 131072) - I * 414645 / 131072,
Rational(6545, 131072) + I * 414645 / 131072
]
assert S(t[0]._get_interval().dx) < 1e-4
assert S(t[1]._get_interval().dx) < 1e-4
assert S(t[1]._get_interval().dy) < 1e-4
assert S(t[2]._get_interval().dx) < 1e-4
assert S(t[2]._get_interval().dy) < 1e-4
# in the following, the actual relative precision is
# less than tested, but it should never be greater
t[0]._reset()
assert [i.eval_rational(n=2) for i in t] == [
Rational(-202201, 2024022),
Rational(104755, 2097152) - I * 6634255 / 2097152,
Rational(104755, 2097152) + I * 6634255 / 2097152
]
assert abs(S(t[0]._get_interval().dx) / t[0]) < 1e-2
assert abs(S(t[1]._get_interval().dx) / t[1]).n() < 1e-2
assert abs(S(t[1]._get_interval().dy) / t[1]).n() < 1e-2
assert abs(S(t[2]._get_interval().dx) / t[2]).n() < 1e-2
assert abs(S(t[2]._get_interval().dy) / t[2]).n() < 1e-2
t[0]._reset()
assert [i.eval_rational(n=3) for i in t] == [
Rational(-202201, 2024022),
Rational(1676045, 33554432) - I * 106148135 / 33554432,
Rational(1676045, 33554432) + I * 106148135 / 33554432
]
assert abs(S(t[0]._get_interval().dx) / t[0]) < 1e-3
assert abs(S(t[1]._get_interval().dx) / t[1]).n() < 1e-3
assert abs(S(t[1]._get_interval().dy) / t[1]).n() < 1e-3
assert abs(S(t[2]._get_interval().dx) / t[2]).n() < 1e-3
assert abs(S(t[2]._get_interval().dy) / t[2]).n() < 1e-3
t[0]._reset()
a = [i.eval_approx(2) for i in t]
assert [str(i) for i in a] == ['-0.10', '0.05 - 3.2*I', '0.05 + 3.2*I']
assert all(abs(((a[i] - t[i]) / t[i]).n()) < 1e-2 for i in range(len(a)))
def _eval_rewrite_as_log(self, x):
return S.ImaginaryUnit/2 * \
(C.log((S(1) - S.ImaginaryUnit * x)/(S(1) + S.ImaginaryUnit * x)))
def With1885(m, u, x):
c = D(u, x)
return Dist(S(1)/c, Subst(Int(x**m, x), x, u), x)
def test_Max():
from sympy.abc import x, y, z
n = Symbol('n', negative=True)
n_ = Symbol('n_', negative=True)
nn = Symbol('nn', nonnegative=True)
nn_ = Symbol('nn_', nonnegative=True)
p = Symbol('p', positive=True)
p_ = Symbol('p_', positive=True)
np = Symbol('np', nonpositive=True)
np_ = Symbol('np_', nonpositive=True)
r = Symbol('r', real=True)
assert Max(5, 4) == 5
# lists
assert Max() == S.NegativeInfinity
assert Max(x) == x
assert Max(x, y) == Max(y, x)
assert Max(x, y, z) == Max(z, y, x)
assert Max(x, Max(y, z)) == Max(z, y, x)
assert Max(x, Min(y, oo)) == Max(x, y)
assert Max(n, -oo, n_, p, 2) == Max(p, 2)
assert Max(n, -oo, n_, p) == p
assert Max(2, x, p, n, -oo, S.NegativeInfinity, n_, p, 2) == Max(2, x, p)
assert Max(0, x, 1, y) == Max(1, x, y)
assert Max(r, r + 1, r - 1) == 1 + r
assert Max(1000, 100, -100, x, p, n) == Max(p, x, 1000)
assert Max(cos(x), sin(x)) == Max(sin(x), cos(x))
assert Max(cos(x), sin(x)).subs(x, 1) == sin(1)
assert Max(cos(x), sin(x)).subs(x, S(1)/2) == cos(S(1)/2)
raises(ValueError, lambda: Max(cos(x), sin(x)).subs(x, I))
raises(ValueError, lambda: Max(I))
raises(ValueError, lambda: Max(I, x))
raises(ValueError, lambda: Max(S.ComplexInfinity, 1))
assert Max(n, -oo, n_, p, 2) == Max(p, 2)
assert Max(n, -oo, n_, p, 1000) == Max(p, 1000)
assert Max(1, x).diff(x) == Heaviside(x - 1)
assert Max(x, 1).diff(x) == Heaviside(x - 1)
assert Max(x**2, 1 + x, 1).diff(x) == \
2*x*Heaviside(x**2 - Max(1, x + 1)) \
+ Heaviside(x - Max(1, x**2) + 1)
e = Max(0, x)
assert e.evalf == e.n
assert e.n().args == (0, x)
# issue 8643
m = Max(p, p_, n, r)
assert m.is_positive is True
assert m.is_nonnegative is True
assert m.is_negative is False
m = Max(n, n_)
assert m.is_positive is False
assert m.is_nonnegative is False
assert m.is_negative is True
m = Max(n, n_, r)
assert m.is_positive is None
assert m.is_nonnegative is None
assert m.is_negative is None
m = Max(n, nn, r)
assert m.is_positive is None
assert m.is_nonnegative is True
assert m.is_negative is False
def replacement1886(u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist((-a*v + b*u)/a, Int(S(1)/u, x), x) + Simp(b*x/a, x)
def test_Min():
from sympy.abc import x, y, z
n = Symbol('n', negative=True)
n_ = Symbol('n_', negative=True)
nn = Symbol('nn', nonnegative=True)
nn_ = Symbol('nn_', nonnegative=True)
p = Symbol('p', positive=True)
p_ = Symbol('p_', positive=True)
np = Symbol('np', nonpositive=True)
np_ = Symbol('np_', nonpositive=True)
r = Symbol('r', real=True)
assert Min(5, 4) == 4
assert Min(-oo, -oo) == -oo
assert Min(-oo, n) == -oo
assert Min(n, -oo) == -oo
assert Min(-oo, np) == -oo
assert Min(np, -oo) == -oo
assert Min(-oo, 0) == -oo
assert Min(0, -oo) == -oo
assert Min(-oo, nn) == -oo
assert Min(nn, -oo) == -oo
assert Min(-oo, p) == -oo
assert Min(p, -oo) == -oo
assert Min(-oo, oo) == -oo
assert Min(oo, -oo) == -oo
assert Min(n, n) == n
assert Min(n, np) == Min(n, np)
assert Min(np, n) == Min(np, n)
assert Min(n, 0) == n
assert Min(0, n) == n
assert Min(n, nn) == n
assert Min(nn, n) == n
assert Min(n, p) == n
assert Min(p, n) == n
assert Min(n, oo) == n
assert Min(oo, n) == n
assert Min(np, np) == np
assert Min(np, 0) == np
assert Min(0, np) == np
assert Min(np, nn) == np
assert Min(nn, np) == np
assert Min(np, p) == np
assert Min(p, np) == np
assert Min(np, oo) == np
assert Min(oo, np) == np
assert Min(0, 0) == 0
assert Min(0, nn) == 0
assert Min(nn, 0) == 0
assert Min(0, p) == 0
assert Min(p, 0) == 0
assert Min(0, oo) == 0
assert Min(oo, 0) == 0
assert Min(nn, nn) == nn
assert Min(nn, p) == Min(nn, p)
assert Min(p, nn) == Min(p, nn)
assert Min(nn, oo) == nn
assert Min(oo, nn) == nn
assert Min(p, p) == p
assert Min(p, oo) == p
assert Min(oo, p) == p
assert Min(oo, oo) == oo
assert Min(n, n_).func is Min
assert Min(nn, nn_).func is Min
assert Min(np, np_).func is Min
assert Min(p, p_).func is Min
# lists
assert Min() == S.Infinity
assert Min(x) == x
assert Min(x, y) == Min(y, x)
assert Min(x, y, z) == Min(z, y, x)
assert Min(x, Min(y, z)) == Min(z, y, x)
assert Min(x, Max(y, -oo)) == Min(x, y)
assert Min(p, oo, n, p, p, p_) == n
assert Min(p_, n_, p) == n_
assert Min(n, oo, -7, p, p, 2) == Min(n, -7)
assert Min(2, x, p, n, oo, n_, p, 2, -2, -2) == Min(-2, x, n, n_)
assert Min(0, x, 1, y) == Min(0, x, y)
assert Min(1000, 100, -100, x, p, n) == Min(n, x, -100)
assert Min(cos(x), sin(x)) == Min(cos(x), sin(x))
assert Min(cos(x), sin(x)).subs(x, 1) == cos(1)
assert Min(cos(x), sin(x)).subs(x, S(1)/2) == sin(S(1)/2)
raises(ValueError, lambda: Min(cos(x), sin(x)).subs(x, I))
raises(ValueError, lambda: Min(I))
raises(ValueError, lambda: Min(I, x))
raises(ValueError, lambda: Min(S.ComplexInfinity, x))
assert Min(1, x).diff(x) == Heaviside(1 - x)
assert Min(x, 1).diff(x) == Heaviside(1 - x)
assert Min(0, -x, 1 - 2*x).diff(x) == -Heaviside(x + Min(0, -2*x + 1)) \
- 2*Heaviside(2*x + Min(0, -x) - 1)
# issue 7619
f = Function('f')
assert Min(1, 2*Min(f(1), 2)) # doesn't fail
# issue 7233
e = Min(0, x)
assert e.evalf == e.n
assert e.n().args == (0, x)
# issue 8643
m = Min(n, p_, n_, r)
assert m.is_positive is False
assert m.is_nonnegative is False
assert m.is_negative is True
m = Min(p, p_)
assert m.is_positive is True
assert m.is_nonnegative is True
assert m.is_negative is False
m = Min(p, nn_, p_)
assert m.is_positive is None
assert m.is_nonnegative is True
assert m.is_negative is False
m = Min(nn, p, r)
assert m.is_positive is None
assert m.is_nonnegative is None
assert m.is_negative is None
def replacement1888(u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist(a/(-a*v + b*u), Int(S(1)/u, x), x) + Dist(b/(-a*v + b*u), Int(S(1)/v, x), x)
def test_atoms():
m = PropertiesOnlyMatrix(2, 2, [1, 2, x, 1 - 1/x])
assert m.atoms() == {S.One, S(2), S.NegativeOne, x}
assert m.atoms(Symbol) == {x}
def replacement1890(u, v, x):
a = D(u, x)
b = D(v, x)
return Simp(-S(2)*atanh(sqrt(v)/Rt(-(-a*v + b*u)/a, S(2)))/(a*Rt(-(-a*v + b*u)/a, S(2))), x)
def test_div():
n = ArithmeticOnlyMatrix(1, 2, [1, 2])
assert n/2 == ArithmeticOnlyMatrix(1, 2, [S.Half, S(2)/2])
def replacement1892(n, u, v, x):
a = D(u, x)
b = D(v, x)
return Simp(v**(n + S(1))*Hypergeometric2F1(S(1), n + S(1), n + S(2), -a*v/(-a*v + b*u))/((n + S(1))*(-a*v + b*u)), x)
def test_parabola_geom():
a, b = symbols('a b')
p1 = Point(0, 0)
p2 = Point(3, 7)
p3 = Point(0, 4)
p4 = Point(6, 0)
p5 = Point(a, a)
d1 = Line(Point(4, 0), Point(4, 9))
d2 = Line(Point(7, 6), Point(3, 6))
d3 = Line(Point(4, 0), slope=oo)
d4 = Line(Point(7, 6), slope=0)
d5 = Line(Point(b, a), slope=oo)
d6 = Line(Point(a, b), slope=0)
half = S.Half
pa1 = Parabola(None, d2)
pa2 = Parabola(directrix=d1)
pa3 = Parabola(p1, d1)
pa4 = Parabola(p2, d2)
pa5 = Parabola(p2, d4)
pa6 = Parabola(p3, d2)
pa7 = Parabola(p2, d1)
pa8 = Parabola(p4, d1)
pa9 = Parabola(p4, d3)
pa10 = Parabola(p5, d5)
pa11 = Parabola(p5, d6)
raises(ValueError,
lambda: Parabola(Point(7, 8, 9), Line(Point(6, 7), Point(7, 7))))
raises(NotImplementedError,
lambda: Parabola(Point(7, 8), Line(Point(3, 7), Point(2, 9))))
raises(ValueError,
lambda: Parabola(Point(0, 2), Line(Point(7, 2), Point(6, 2))))
raises(ValueError, lambda: Parabola(Point(7, 8), Point(3, 8)))
# Basic Stuff
assert pa1.focus == Point(0, 0)
assert pa1.ambient_dimension == S(2)
assert pa2 == pa3
assert pa4 != pa7
assert pa6 != pa7
assert pa6.focus == Point2D(0, 4)
assert pa6.focal_length == 1
assert pa6.p_parameter == -1
assert pa6.vertex == Point2D(0, 5)
assert pa6.eccentricity == 1
assert pa7.focus == Point2D(3, 7)
assert pa7.focal_length == half
assert pa7.p_parameter == -half
assert pa7.vertex == Point2D(7 * half, 7)
assert pa4.focal_length == half
assert pa4.p_parameter == half
assert pa4.vertex == Point2D(3, 13 * half)
assert pa8.focal_length == 1
assert pa8.p_parameter == 1
assert pa8.vertex == Point2D(5, 0)
assert pa4.focal_length == pa5.focal_length
assert pa4.p_parameter == pa5.p_parameter
assert pa4.vertex == pa5.vertex
assert pa4.equation() == pa5.equation()
assert pa8.focal_length == pa9.focal_length
assert pa8.p_parameter == pa9.p_parameter
assert pa8.vertex == pa9.vertex
assert pa8.equation() == pa9.equation()
assert pa10.focal_length == pa11.focal_length == sqrt(
(a - b)**2) / 2 # if a, b real == abs(a - b)/2
assert pa11.vertex == Point(*pa10.vertex[::-1]) == Point(
a, a - sqrt(
(a - b)**2) * sign(a - b) / 2) # change axis x->y, y->x on pa10
def replacement1894(u, v, x):
a = D(u, x)
b = D(v, x)
return Simp(S(2)*ArcTan(sqrt(u)*Rt(-a*b, S(2))/(a*sqrt(v)))/Rt(-a*b, S(2)), x)
def test_AccumBounds_exponent():
# base is 0
z = 0**B(a, a + S.Half)
assert z.subs(a, 0) == B(0, 1)
assert z.subs(a, 1) == 0
p = z.subs(a, -1)
assert p.is_Pow and p.args == (0, B(-1, -S.Half))
# base > 0
# when base is 1 the type of bounds does not matter
assert 1**B(a, a + 1) == 1
# otherwise we need to know if 0 is in the bounds
assert S.Half**B(-2, 2) == B(S(1) / 4, 4)
assert 2**B(-2, 2) == B(S(1) / 4, 4)
# +eps may introduce +oo
# if there is a negative integer exponent
assert B(0, 1)**B(S(1) / 2, 1) == B(0, 1)
assert B(0, 1)**B(0, 1) == B(0, 1)
# positive bases have positive bounds
assert B(2, 3)**B(-3, -2) == B(S(1) / 27, S(1) / 4)
assert B(2, 3)**B(-3, 2) == B(S(1) / 27, 9)
# bounds generating imaginary parts unevaluated
assert unchanged(Pow, B(-1, 1), B(1, 2))
assert B(0, S(1) / 2)**B(1, oo) == B(0, S(1) / 2)
assert B(0, 1)**B(1, oo) == B(0, oo)
assert B(0, 2)**B(1, oo) == B(0, oo)
assert B(0, oo)**B(1, oo) == B(0, oo)
assert B(S(1) / 2, 1)**B(1, oo) == B(0, oo)
assert B(S(1) / 2, 1)**B(-oo, -1) == B(0, oo)
assert B(S(1) / 2, 1)**B(-oo, oo) == B(0, oo)
assert B(S(1) / 2, 2)**B(1, oo) == B(0, oo)
assert B(S(1) / 2, 2)**B(-oo, -1) == B(0, oo)
assert B(S(1) / 2, 2)**B(-oo, oo) == B(0, oo)
assert B(S(1) / 2, oo)**B(1, oo) == B(0, oo)
assert B(S(1) / 2, oo)**B(-oo, -1) == B(0, oo)
assert B(S(1) / 2, oo)**B(-oo, oo) == B(0, oo)
assert B(1, 2)**B(1, oo) == B(0, oo)
assert B(1, 2)**B(-oo, -1) == B(0, oo)
assert B(1, 2)**B(-oo, oo) == B(0, oo)
assert B(1, oo)**B(1, oo) == B(0, oo)
assert B(1, oo)**B(-oo, -1) == B(0, oo)
assert B(1, oo)**B(-oo, oo) == B(0, oo)
assert B(2, oo)**B(1, oo) == B(2, oo)
assert B(2, oo)**B(-oo, -1) == B(0, S(1) / 2)
assert B(2, oo)**B(-oo, oo) == B(0, oo)
def replacement1896(m, n, u, v, x):
a = D(u, x)
b = D(v, x)
return -Dist(b*n/(a*(m + S(1))), Int(u**(m + S(1))*v**(n + S(-1)), x), x) + Simp(u**(m + S(1))*v**n/(a*(m + S(1))), x)
def piecewise_linear():
from sympy.integrals.rubi.constraints import cons1092, cons19, cons1093, cons89, cons90, cons1094, cons91, cons25, cons74, cons68, cons4, cons1095, cons216, cons685, cons102, cons103, cons1096, cons1097, cons33, cons96, cons358, cons1098, cons21, cons1099, cons2, cons3
pattern1885 = Pattern(Integral(u_**WC('m', S(1)), x_), cons19, cons1092)
rule1885 = ReplacementRule(pattern1885, With1885)
pattern1886 = Pattern(Integral(v_/u_, x_), cons1093, CustomConstraint(With1886))
rule1886 = ReplacementRule(pattern1886, replacement1886)
pattern1887 = Pattern(Integral(v_**n_/u_, x_), cons1093, cons89, cons90, cons1094, CustomConstraint(With1887))
rule1887 = ReplacementRule(pattern1887, replacement1887)
pattern1888 = Pattern(Integral(S(1)/(u_*v_), x_), cons1093, CustomConstraint(With1888))
rule1888 = ReplacementRule(pattern1888, replacement1888)
pattern1889 = Pattern(Integral(S(1)/(u_*sqrt(v_)), x_), cons1093, CustomConstraint(With1889))
rule1889 = ReplacementRule(pattern1889, replacement1889)
pattern1890 = Pattern(Integral(S(1)/(u_*sqrt(v_)), x_), cons1093, CustomConstraint(With1890))
rule1890 = ReplacementRule(pattern1890, replacement1890)
pattern1891 = Pattern(Integral(v_**n_/u_, x_), cons1093, cons89, cons91, CustomConstraint(With1891))
rule1891 = ReplacementRule(pattern1891, replacement1891)
pattern1892 = Pattern(Integral(v_**n_/u_, x_), cons1093, cons25, CustomConstraint(With1892))
rule1892 = ReplacementRule(pattern1892, replacement1892)
pattern1893 = Pattern(Integral(S(1)/(sqrt(u_)*sqrt(v_)), x_), cons1093, CustomConstraint(With1893))
rule1893 = ReplacementRule(pattern1893, replacement1893)
pattern1894 = Pattern(Integral(S(1)/(sqrt(u_)*sqrt(v_)), x_), cons1093, CustomConstraint(With1894))
rule1894 = ReplacementRule(pattern1894, replacement1894)
pattern1895 = Pattern(Integral(u_**m_*v_**n_, x_), cons19, cons4, cons1093, cons74, cons68, CustomConstraint(With1895))
rule1895 = ReplacementRule(pattern1895, replacement1895)
pattern1896 = Pattern(Integral(u_**m_*v_**WC('n', S(1)), x_), cons19, cons4, cons1093, cons68, cons1095, CustomConstraint(With1896))
rule1896 = ReplacementRule(pattern1896, replacement1896)
pattern1897 = Pattern(Integral(u_**m_*v_**WC('n', S(1)), x_), cons1093, cons216, cons89, cons90, cons685, cons102, cons103, CustomConstraint(With1897))
rule1897 = ReplacementRule(pattern1897, replacement1897)
pattern1898 = Pattern(Integral(u_**m_*v_**n_, x_), cons1093, cons685, cons1096, cons1097, CustomConstraint(With1898))
rule1898 = ReplacementRule(pattern1898, replacement1898)
pattern1899 = Pattern(Integral(u_**m_*v_**n_, x_), cons1093, cons216, cons33, cons96, CustomConstraint(With1899))
rule1899 = ReplacementRule(pattern1899, replacement1899)
pattern1900 = Pattern(Integral(u_**m_*v_**n_, x_), cons1093, cons358, cons1098, CustomConstraint(With1900))
rule1900 = ReplacementRule(pattern1900, replacement1900)
pattern1901 = Pattern(Integral(u_**m_*v_**n_, x_), cons1093, cons21, cons25, CustomConstraint(With1901))
rule1901 = ReplacementRule(pattern1901, replacement1901)
pattern1902 = Pattern(Integral(u_**WC('n', S(1))*log(x_*WC('b', S(1)) + WC('a', S(0))), x_), cons2, cons3, cons1092, cons1099, cons89, cons90)
rule1902 = ReplacementRule(pattern1902, With1902)
pattern1903 = Pattern(Integral(u_**WC('n', S(1))*(x_*WC('b', S(1)) + WC('a', S(0)))**WC('m', S(1))*log(x_*WC('b', S(1)) + WC('a', S(0))), x_), cons2, cons3, cons19, cons1092, cons1099, cons89, cons90, cons68)
rule1903 = ReplacementRule(pattern1903, With1903)
return [rule1885, rule1886, rule1887, rule1888, rule1889, rule1890, rule1891, rule1892, rule1893, rule1894, rule1895, rule1896, rule1897, rule1898, rule1899, rule1900, rule1901, rule1902, rule1903, ]
def replacement1900(m, n, u, v, x):
a = D(u, x)
b = D(v, x)
return Dist(b*(m + n + S(2))/((m + S(1))*(-a*v + b*u)), Int(u**(m + S(1))*v**n, x), x) - Simp(u**(m + S(1))*v**(n + S(1))/((m + S(1))*(-a*v + b*u)), x)
def test_rm_id():
rmzeros = rm_id(lambda x: x == 0)
assert rmzeros(Basic(S(0), S(1))) == Basic(S(1))
assert rmzeros(Basic(S(0), S(0))) == Basic(S(0))
assert rmzeros(Basic(S(2), S(1))) == Basic(S(2), S(1))
