def test_finally(): try: with assuming(Q.integer(x)): 1/0 except ZeroDivisionError: pass assert not ask(Q.integer(x))
def test_float_1(): z = 1.0 assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == True assert ask(Q.rational(z)) == True assert ask(Q.real(z)) == True assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == False assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == True assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == True assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == True z = 7.2123 assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == False assert ask(Q.rational(z)) == True assert ask(Q.real(z)) == True assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == False assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == True assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False
def Pow(expr, assumptions): """ Integer**Integer -> !Prime """ if expr.is_number: return AskPrimeHandler._number(expr, assumptions) if ask(Q.integer(expr.exp), assumptions) and ask(Q.integer(expr.base), assumptions): return False
def test_custom_context(): """Test ask with custom assumptions context""" x = symbols('x') assert ask(Q.integer(x)) == None local_context = AssumptionsContext() local_context.add(Q.integer(x)) assert ask(Q.integer(x), context = local_context) == True assert ask(Q.integer(x)) == None
def test_remove_safe(): global_assumptions.add(Q.integer(x)) with assuming(): assert ask(Q.integer(x)) global_assumptions.remove(Q.integer(x)) assert not ask(Q.integer(x)) assert ask(Q.integer(x)) global_assumptions.clear() # for the benefit of other tests
def test_global(): """Test ask with global assumptions""" x = symbols('x') assert ask(Q.integer(x)) == None global_assumptions.add(Q.integer(x)) assert ask(Q.integer(x)) == True global_assumptions.clear() assert ask(Q.integer(x)) == None
def Pow(expr, assumptions): """ Real**Integer -> Real Positive**Real -> Real Real**(Integer/Even) -> Real if base is nonnegative Real**(Integer/Odd) -> Real Imaginary**(Integer/Even) -> Real Imaginary**(Integer/Odd) -> not Real Imaginary**Real -> ? since Real could be 0 (giving real) or 1 (giving imaginary) b**Imaginary -> Real if log(b) is imaginary and b != 0 and exponent != integer multiple of I*pi/log(b) Real**Real -> ? e.g. sqrt(-1) is imaginary and sqrt(2) is not """ if expr.is_number: return AskRealHandler._number(expr, assumptions) if expr.base.func == exp: if ask(Q.imaginary(expr.base.args[0]), assumptions): if ask(Q.imaginary(expr.exp), assumptions): return True # If the i = (exp's arg)/(I*pi) is an integer or half-integer # multiple of I*pi then 2*i will be an integer. In addition, # exp(i*I*pi) = (-1)**i so the overall realness of the expr # can be determined by replacing exp(i*I*pi) with (-1)**i. i = expr.base.args[0]/I/pi if ask(Q.integer(2*i), assumptions): return ask(Q.real(((-1)**i)**expr.exp), assumptions) return if ask(Q.imaginary(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): odd = ask(Q.odd(expr.exp), assumptions) if odd is not None: return not odd return if ask(Q.imaginary(expr.exp), assumptions): imlog = ask(Q.imaginary(log(expr.base)), assumptions) if imlog is not None: # I**i -> real, log(I) is imag; # (2*I)**i -> complex, log(2*I) is not imag return imlog if ask(Q.real(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if expr.exp.is_Rational and \ ask(Q.even(expr.exp.q), assumptions): return ask(Q.positive(expr.base), assumptions) elif ask(Q.integer(expr.exp), assumptions): return True elif ask(Q.positive(expr.base), assumptions): return True elif ask(Q.negative(expr.base), assumptions): return False
def test_I(): I = S.ImaginaryUnit z = I assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == False assert ask(Q.rational(z)) == False assert ask(Q.real(z)) == False assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == False assert ask(Q.imaginary(z)) == True assert ask(Q.positive(z)) == False assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False z = 1 + I assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == False assert ask(Q.rational(z)) == False assert ask(Q.real(z)) == False assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == False assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == False assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False z = I*(1+I) assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == False assert ask(Q.rational(z)) == False assert ask(Q.real(z)) == False assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == False assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == False assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False
def Pow(expr, assumptions): """ Imaginary**Odd -> Imaginary Imaginary**Even -> Real b**Imaginary -> !Imaginary if exponent is an integer multiple of I*pi/log(b) Imaginary**Real -> ? Positive**Real -> Real Negative**Integer -> Real Negative**(Integer/2) -> Imaginary Negative**Real -> not Imaginary if exponent is not Rational """ if expr.is_number: return AskImaginaryHandler._number(expr, assumptions) if expr.base.func == exp: if ask(Q.imaginary(expr.base.args[0]), assumptions): if ask(Q.imaginary(expr.exp), assumptions): return False i = expr.base.args[0]/I/pi if ask(Q.integer(2*i), assumptions): return ask(Q.imaginary(((-1)**i)**expr.exp), assumptions) if ask(Q.imaginary(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): odd = ask(Q.odd(expr.exp), assumptions) if odd is not None: return odd return if ask(Q.imaginary(expr.exp), assumptions): imlog = ask(Q.imaginary(log(expr.base)), assumptions) if imlog is not None: return False # I**i -> real; (2*I)**i -> complex ==> not imaginary if ask(Q.real(expr.base) & Q.real(expr.exp), assumptions): if ask(Q.positive(expr.base), assumptions): return False else: rat = ask(Q.rational(expr.exp), assumptions) if not rat: return rat if ask(Q.integer(expr.exp), assumptions): return False else: half = ask(Q.integer(2*expr.exp), assumptions) if half: return ask(Q.negative(expr.base), assumptions) return half
def MatPow(expr, assumptions): # only for integer powers base, exp = expr.args int_exp = ask(Q.integer(exp), assumptions) if int_exp: return ask(Q.unitary(base), assumptions) return None
def test_negative(): x, y = symbols('x,y') assert ask(Q.negative(x), Q.negative(x)) == True assert ask(Q.negative(x), Q.positive(x)) == False assert ask(Q.negative(x), ~Q.real(x)) == False assert ask(Q.negative(x), Q.prime(x)) == False assert ask(Q.negative(x), ~Q.prime(x)) == None assert ask(Q.negative(-x), Q.positive(x)) == True assert ask(Q.negative(-x), ~Q.positive(x)) == None assert ask(Q.negative(-x), Q.negative(x)) == False assert ask(Q.negative(-x), Q.positive(x)) == True assert ask(Q.negative(x-1), Q.negative(x)) == True assert ask(Q.negative(x+y)) == None assert ask(Q.negative(x+y), Q.negative(x)) == None assert ask(Q.negative(x+y), Q.negative(x) & Q.negative(y)) == True assert ask(Q.negative(x**2)) == None assert ask(Q.negative(x**2), Q.real(x)) == False assert ask(Q.negative(x**1.4), Q.real(x)) == None assert ask(Q.negative(x*y)) == None assert ask(Q.negative(x*y), Q.positive(x) & Q.positive(y)) == False assert ask(Q.negative(x*y), Q.positive(x) & Q.negative(y)) == True assert ask(Q.negative(x*y), Q.complex(x) & Q.complex(y)) == None assert ask(Q.negative(x**y)) == None assert ask(Q.negative(x**y), Q.negative(x) & Q.even(y)) == False assert ask(Q.negative(x**y), Q.negative(x) & Q.odd(y)) == True assert ask(Q.negative(x**y), Q.positive(x) & Q.integer(y)) == False assert ask(Q.negative(Abs(x))) == False
def Pow(expr, assumptions): """ Imaginary**integer -> Imaginary if integer % 2 == 1 Imaginary**integer -> real if integer % 2 == 0 Imaginary**Imaginary -> ? Imaginary**Real -> ? """ if expr.is_number: return AskImaginaryHandler._number(expr, assumptions) if ask(Q.imaginary(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if ask(Q.odd(expr.exp), assumptions): return True elif ask(Q.even(expr.exp), assumptions): return False elif ask(Q.real(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if expr.exp.is_Rational and \ ask(Q.even(expr.exp.q), assumptions): return ask(Q.negative(expr.base),assumptions) elif ask(Q.integer(expr.exp), assumptions): return False elif ask(Q.positive(expr.base), assumptions): return False elif ask(Q.negative(expr.base), assumptions): return True
def MatPow(expr, assumptions): # only for integer powers base, exp = expr.args int_exp = ask(Q.integer(exp), assumptions) if int_exp and ask(~Q.negative(exp), assumptions): return ask(Q.fullrank(base), assumptions) return None
def Mul(expr, assumptions): """ Integer*Integer -> Integer Integer*Irrational -> !Integer Odd/Even -> !Integer Integer*Rational -> ? """ if expr.is_number: return AskIntegerHandler._number(expr, assumptions) _output = True for arg in expr.args: if not ask(Q.integer(arg), assumptions): if arg.is_Rational: if arg.q == 2: return ask(Q.even(2*expr), assumptions) if ~(arg.q & 1): return None elif ask(Q.irrational(arg), assumptions): if _output: _output = False else: return else: return else: return _output
def Basic(expr, assumptions): _integer = ask(Q.integer(expr), assumptions) if _integer: _even = ask(Q.even(expr), assumptions) if _even is None: return None return not _even return _integer
def Mul(expr, assumptions): """ Even * Integer -> Even Even * Odd -> Even Integer * Odd -> ? Odd * Odd -> Odd """ if expr.is_number: return AskEvenHandler._number(expr, assumptions) even, odd, irrational = False, 0, False for arg in expr.args: # check for all integers and at least one even if ask(Q.integer(arg), assumptions): if ask(Q.even(arg), assumptions): even = True elif ask(Q.odd(arg), assumptions): odd += 1 elif ask(Q.irrational(arg), assumptions): # one irrational makes the result False # two makes it undefined if irrational: break irrational = True else: break else: if irrational: return False if even: return True if odd == len(expr.args): return False
def refine_exp(expr, assumptions): """ Handler for exponential function. >>> from sympy import Symbol, Q, exp, I, pi >>> from sympy.assumptions.refine import refine_exp >>> from sympy.abc import x >>> refine_exp(exp(pi*I*2*x), Q.real(x)) >>> refine_exp(exp(pi*I*2*x), Q.integer(x)) 1 """ arg = expr.args[0] if arg.is_Mul: coeff = arg.as_coefficient(S.Pi*S.ImaginaryUnit) if coeff: if ask(Q.integer(2*coeff), assumptions): if ask(Q.even(coeff), assumptions): return S.One elif ask(Q.odd(coeff), assumptions): return S.NegativeOne elif ask(Q.even(coeff + S.Half), assumptions): return -S.ImaginaryUnit elif ask(Q.odd(coeff + S.Half), assumptions): return S.ImaginaryUnit
def Pow(expr, assumptions): """ Real**Integer -> Real Positive**Real -> Real Real**(Integer/Even) -> Real if base is nonnegative Real**(Integer/Odd) -> Real Real**Imaginary -> ? Imaginary**Real -> ? Real**Real -> ? """ if expr.is_number: return AskRealHandler._number(expr, assumptions) if ask(Q.imaginary(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if ask(Q.odd(expr.exp), assumptions): return False elif ask(Q.even(expr.exp), assumptions): return True elif ask(Q.real(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if expr.exp.is_Rational and \ ask(Q.even(expr.exp.q), assumptions): return ask(Q.positive(expr.base), assumptions) elif ask(Q.integer(expr.exp), assumptions): return True elif ask(Q.positive(expr.base), assumptions): return True elif ask(Q.negative(expr.base), assumptions): return False
def Pow(expr, assumptions): """ Imaginary**integer/odd -> Imaginary Imaginary**integer/even -> Real if integer % 2 == 0 b**Imaginary -> !Imaginary if exponent is an integer multiple of I*pi/log(b) Imaginary**Real -> ? Negative**even root -> Imaginary Negative**odd root -> Real Negative**Real -> Imaginary Real**Integer -> Real Real**Positive -> Real """ if expr.is_number: return AskImaginaryHandler._number(expr, assumptions) if expr.base.func == C.exp: if ask(Q.imaginary(expr.base.args[0]), assumptions): if ask(Q.imaginary(expr.exp), assumptions): return False i = expr.base.args[0]/I/pi if ask(Q.integer(2*i), assumptions): return ask(Q.imaginary(((-1)**i)**expr.exp), assumptions) if ask(Q.imaginary(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): odd = ask(Q.odd(expr.exp), assumptions) if odd is not None: return odd return if ask(Q.imaginary(expr.exp), assumptions): imlog = ask(Q.imaginary(C.log(expr.base)), assumptions) if imlog is not None: return False # I**i -> real; (2*I)**i -> complex ==> not imaginary if ask(Q.real(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if ask(Q.rational(expr.exp) & Q.even(denom(expr.exp)), assumptions): return ask(Q.negative(expr.base), assumptions) elif ask(Q.integer(expr.exp), assumptions): return False elif ask(Q.positive(expr.base), assumptions): return False elif ask(Q.negative(expr.base), assumptions): return True
def Mul(expr, assumptions): if expr.is_number: return AskPrimeHandler._number(expr, assumptions) for arg in expr.args: if not ask(Q.integer(arg), assumptions): return None for arg in expr.args: if arg.is_number and arg.is_composite: return False
def MatPow(expr, assumptions): # only for integer powers base, exp = expr.args int_exp = ask(Q.integer(exp), assumptions) if not int_exp: return None if exp.is_negative == False: return ask(Q.integer_elements(base), assumptions) return None
def Pow(expr, assumptions): """ Hermitian**Integer -> Hermitian """ if expr.is_number: return AskRealHandler._number(expr, assumptions) if ask(Q.hermitian(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return True
def test_real(): x, y = symbols('x,y') assert ask(Q.real(x)) == None assert ask(Q.real(x), Q.real(x)) == True assert ask(Q.real(x), Q.nonzero(x)) == True assert ask(Q.real(x), Q.positive(x)) == True assert ask(Q.real(x), Q.negative(x)) == True assert ask(Q.real(x), Q.integer(x)) == True assert ask(Q.real(x), Q.even(x)) == True assert ask(Q.real(x), Q.prime(x)) == True assert ask(Q.real(x/sqrt(2)), Q.real(x)) == True assert ask(Q.real(x/sqrt(-2)), Q.real(x)) == False I = S.ImaginaryUnit assert ask(Q.real(x+1), Q.real(x)) == True assert ask(Q.real(x+I), Q.real(x)) == False assert ask(Q.real(x+I), Q.complex(x)) == None assert ask(Q.real(2*x), Q.real(x)) == True assert ask(Q.real(I*x), Q.real(x)) == False assert ask(Q.real(I*x), Q.imaginary(x)) == True assert ask(Q.real(I*x), Q.complex(x)) == None assert ask(Q.real(x**2), Q.real(x)) == True assert ask(Q.real(sqrt(x)), Q.negative(x)) == False assert ask(Q.real(x**y), Q.real(x) & Q.integer(y)) == True assert ask(Q.real(x**y), Q.real(x) & Q.real(y)) == None assert ask(Q.real(x**y), Q.positive(x) & Q.real(y)) == True # trigonometric functions assert ask(Q.real(sin(x))) == None assert ask(Q.real(cos(x))) == None assert ask(Q.real(sin(x)), Q.real(x)) == True assert ask(Q.real(cos(x)), Q.real(x)) == True # exponential function assert ask(Q.real(exp(x))) == None assert ask(Q.real(exp(x)), Q.real(x)) == True assert ask(Q.real(x + exp(x)), Q.real(x)) == True # Q.complexes assert ask(Q.real(re(x))) == True assert ask(Q.real(im(x))) == True
def Mul(expr, assumptions): if expr.is_number: return AskPrimeHandler._number(expr, assumptions) for arg in expr.args: if ask(Q.integer(arg), assumptions): pass else: break else: # a product of integers can't be a prime return False
def Basic(expr, assumptions): _positive = ask(Q.positive(expr), assumptions) if _positive: _integer = ask(Q.integer(expr), assumptions) if _integer: _prime = ask(Q.prime(expr), assumptions) if _prime is None: return return not _prime else: return _integer else: return _positive
def Pow(expr, assumptions): if expr.is_number: return AskEvenHandler._number(expr, assumptions) if ask(Q.integer(expr.exp), assumptions): if ask(Q.positive(expr.exp), assumptions): return ask(Q.even(expr.base), assumptions) elif ask(~Q.negative(expr.exp) & Q.odd(expr.base), assumptions): return False elif expr.base is S.NegativeOne: return False
def MatPow(expr, assumptions): # only for integer powers base, exp = expr.args int_exp = ask(Q.integer(exp), assumptions) if not int_exp: return None non_negative = ask(~Q.negative(exp), assumptions) if (non_negative or non_negative == False and ask(Q.invertible(base), assumptions)): return ask(Q.complex_elements(base), assumptions) return None
def Pow(expr, assumptions): """ Rational ** Integer -> Rational Irrational ** Rational -> Irrational Rational ** Irrational -> ? """ if ask(Q.integer(expr.exp), assumptions): return ask(Q.rational(expr.base), assumptions) elif ask(Q.rational(expr.exp), assumptions): if ask(Q.prime(expr.base), assumptions): return False
def _(expr, assumptions): # only for integer powers base, exp = expr.args int_exp = ask(Q.integer(exp), assumptions) if not int_exp: return None non_negative = ask(~Q.negative(exp), assumptions) if (non_negative or non_negative == False and ask(Q.invertible(base), assumptions)): return ask(Q.diagonal(base), assumptions) return None
def _(expr, assumptions): """ * Hermitian**Integer -> Hermitian """ if expr.is_number: return None if expr.base == E: if ask(Q.hermitian(expr.exp), assumptions): return True return if ask(Q.hermitian(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return True
def test_prime(): x, y = symbols('x,y') assert ask(Q.prime(x), Q.prime(x)) == True assert ask(Q.prime(x), ~Q.prime(x)) == False assert ask(Q.prime(x), Q.integer(x)) == None assert ask(Q.prime(x), ~Q.integer(x)) == False assert ask(Q.prime(2*x), Q.integer(x)) == False assert ask(Q.prime(x*y)) == None assert ask(Q.prime(x*y), Q.prime(x)) == None assert ask(Q.prime(x*y), Q.integer(x) & Q.integer(y)) == False assert ask(Q.prime(x**2), Q.integer(x)) == False assert ask(Q.prime(x**2), Q.prime(x)) == False assert ask(Q.prime(x**y), Q.integer(x) & Q.integer(y)) == False
def test_prime(): x, y = symbols('x,y') assert ask(Q.prime(x), Q.prime(x)) == True assert ask(Q.prime(x), ~Q.prime(x)) == False assert ask(Q.prime(x), Q.integer(x)) == None assert ask(Q.prime(x), ~Q.integer(x)) == False assert ask(Q.prime(2 * x), Q.integer(x)) == False assert ask(Q.prime(x * y)) == None assert ask(Q.prime(x * y), Q.prime(x)) == None assert ask(Q.prime(x * y), Q.integer(x) & Q.integer(y)) == False assert ask(Q.prime(x**2), Q.integer(x)) == False assert ask(Q.prime(x**2), Q.prime(x)) == False assert ask(Q.prime(x**y), Q.integer(x) & Q.integer(y)) == False
def test_composite_proposition(): from sympy.logic.boolalg import Equivalent, Implies x = symbols('x') assert ask(True) is True assert ask(~Q.negative(x), Q.positive(x)) is True assert ask(~Q.real(x), Q.commutative(x)) is None assert ask(Q.negative(x) & Q.integer(x), Q.positive(x)) is False assert ask(Q.negative(x) & Q.integer(x)) is None assert ask(Q.real(x) | Q.integer(x), Q.positive(x)) is True assert ask(Q.real(x) | Q.integer(x)) is None assert ask(Q.real(x) >> Q.positive(x), Q.negative(x)) is False assert ask(Implies(Q.real(x), Q.positive(x), evaluate=False), Q.negative(x)) is False assert ask(Implies(Q.real(x), Q.positive(x), evaluate=False)) is None assert ask(Equivalent(Q.integer(x), Q.even(x)), Q.even(x)) is True assert ask(Equivalent(Q.integer(x), Q.even(x))) is None assert ask(Equivalent(Q.positive(x), Q.integer(x)), Q.integer(x)) is None
def _(expr, assumptions): """ * Hermitian**Integer -> Hermitian """ if expr.is_number: raise MDNotImplementedError if expr.base == E: if ask(Q.hermitian(expr.exp), assumptions): return True raise MDNotImplementedError if ask(Q.hermitian(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return True raise MDNotImplementedError
def Pow(expr, assumptions): """ Hermitian**Integer -> !Antihermitian Antihermitian**Even -> !Antihermitian Antihermitian**Odd -> Antihermitian """ if expr.is_number: return AskImaginaryHandler._number(expr, assumptions) if ask(Q.hermitian(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return False elif ask(Q.antihermitian(expr.base), assumptions): if ask(Q.even(expr.exp), assumptions): return False elif ask(Q.odd(expr.exp), assumptions): return True
def _(expr, assumptions): """ * Hermitian**Integer -> !Antihermitian * Antihermitian**Even -> !Antihermitian * Antihermitian**Odd -> Antihermitian """ if expr.is_number: return None if ask(Q.hermitian(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return False elif ask(Q.antihermitian(expr.base), assumptions): if ask(Q.even(expr.exp), assumptions): return False elif ask(Q.odd(expr.exp), assumptions): return True
def _(expr, assumptions): """ * Imaginary**Odd -> Imaginary * Imaginary**Even -> Real * b**Imaginary -> !Imaginary if exponent is an integer multiple of I*pi/log(b) * Imaginary**Real -> ? * Positive**Real -> Real * Negative**Integer -> Real * Negative**(Integer/2) -> Imaginary * Negative**Real -> not Imaginary if exponent is not Rational """ if expr.is_number: return _Imaginary_number(expr, assumptions) if expr.base == E: a = expr.exp / I / pi return ask(Q.integer(2 * a) & ~Q.integer(a), assumptions) if expr.base.func == exp or (expr.base.is_Pow and expr.base.base == E): if ask(Q.imaginary(expr.base.exp), assumptions): if ask(Q.imaginary(expr.exp), assumptions): return False i = expr.base.exp / I / pi if ask(Q.integer(2 * i), assumptions): return ask(Q.imaginary((S.NegativeOne**i)**expr.exp), assumptions) if ask(Q.imaginary(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): odd = ask(Q.odd(expr.exp), assumptions) if odd is not None: return odd return if ask(Q.imaginary(expr.exp), assumptions): imlog = ask(Q.imaginary(log(expr.base)), assumptions) if imlog is not None: # I**i -> real; (2*I)**i -> complex ==> not imaginary return False if ask(Q.real(expr.base) & Q.real(expr.exp), assumptions): if ask(Q.positive(expr.base), assumptions): return False else: rat = ask(Q.rational(expr.exp), assumptions) if not rat: return rat if ask(Q.integer(expr.exp), assumptions): return False else: half = ask(Q.integer(2 * expr.exp), assumptions) if half: return ask(Q.negative(expr.base), assumptions) return half
def test_E(): z = S.Exp1 assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == False assert ask(Q.rational(z)) == False assert ask(Q.real(z)) == True assert ask(Q.complex(z)) == True assert ask(Q.irrational(z)) == True assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == True assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == False assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == False assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False
def test_zero_0(): z = Integer(0) assert ask(Q.nonzero(z)) == False assert ask(Q.commutative(z)) == True assert ask(Q.integer(z)) == True assert ask(Q.rational(z)) == True assert ask(Q.real(z)) == True assert ask(Q.complex(z)) == True assert ask(Q.imaginary(z)) == False assert ask(Q.positive(z)) == False assert ask(Q.negative(z)) == False assert ask(Q.even(z)) == True assert ask(Q.odd(z)) == False assert ask(Q.bounded(z)) == True assert ask(Q.infinitesimal(z)) == True assert ask(Q.prime(z)) == False assert ask(Q.composite(z)) == False
def _(expr, assumptions): _positive = ask(Q.positive(expr), assumptions) if _positive: _integer = ask(Q.integer(expr), assumptions) if _integer: _prime = ask(Q.prime(expr), assumptions) if _prime is None: return # Positive integer which is not prime is not # necessarily composite if expr.equals(1): return False return not _prime else: return _integer else: return _positive
def _(expr, assumptions): """ * Rational ** Integer -> Rational * Irrational ** Rational -> Irrational * Rational ** Irrational -> ? """ if expr.base == E: x = expr.exp if ask(Q.rational(x), assumptions): return ask(~Q.nonzero(x), assumptions) return if ask(Q.integer(expr.exp), assumptions): return ask(Q.rational(expr.base), assumptions) elif ask(Q.rational(expr.exp), assumptions): if ask(Q.prime(expr.base), assumptions): return False
def test_Rational_number(): r = Rational(3, 4) assert ask(Q.commutative(r)) == True assert ask(Q.integer(r)) == False assert ask(Q.rational(r)) == True assert ask(Q.real(r)) == True assert ask(Q.complex(r)) == True assert ask(Q.irrational(r)) == False assert ask(Q.imaginary(r)) == False assert ask(Q.positive(r)) == True assert ask(Q.negative(r)) == False assert ask(Q.even(r)) == False assert ask(Q.odd(r)) == False assert ask(Q.bounded(r)) == True assert ask(Q.infinitesimal(r)) == False assert ask(Q.prime(r)) == False assert ask(Q.composite(r)) == False r = Rational(1, 4) assert ask(Q.positive(r)) == True assert ask(Q.negative(r)) == False r = Rational(5, 4) assert ask(Q.negative(r)) == False assert ask(Q.positive(r)) == True r = Rational(5, 3) assert ask(Q.positive(r)) == True assert ask(Q.negative(r)) == False r = Rational(-3, 4) assert ask(Q.positive(r)) == False assert ask(Q.negative(r)) == True r = Rational(-1, 4) assert ask(Q.positive(r)) == False assert ask(Q.negative(r)) == True r = Rational(-5, 4) assert ask(Q.negative(r)) == True assert ask(Q.positive(r)) == False r = Rational(-5, 3) assert ask(Q.positive(r)) == False assert ask(Q.negative(r)) == True
def test_infinity(): oo = S.Infinity assert ask(Q.commutative(oo)) == True assert ask(Q.integer(oo)) == False assert ask(Q.rational(oo)) == False assert ask(Q.real(oo)) == False assert ask(Q.extended_real(oo)) == True assert ask(Q.complex(oo)) == False assert ask(Q.irrational(oo)) == False assert ask(Q.imaginary(oo)) == False assert ask(Q.positive(oo)) == True assert ask(Q.negative(oo)) == False assert ask(Q.even(oo)) == False assert ask(Q.odd(oo)) == False assert ask(Q.bounded(oo)) == False assert ask(Q.infinitesimal(oo)) == False assert ask(Q.prime(oo)) == False assert ask(Q.composite(oo)) == False
def test_neg_infinity(): mm = S.NegativeInfinity assert ask(Q.commutative(mm)) == True assert ask(Q.integer(mm)) == False assert ask(Q.rational(mm)) == False assert ask(Q.real(mm)) == False assert ask(Q.extended_real(mm)) == True assert ask(Q.complex(mm)) == False assert ask(Q.irrational(mm)) == False assert ask(Q.imaginary(mm)) == False assert ask(Q.positive(mm)) == False assert ask(Q.negative(mm)) == True assert ask(Q.even(mm)) == False assert ask(Q.odd(mm)) == False assert ask(Q.bounded(mm)) == False assert ask(Q.infinitesimal(mm)) == False assert ask(Q.prime(mm)) == False assert ask(Q.composite(mm)) == False
def test_nan(): nan = S.NaN assert ask(Q.commutative(nan)) == True assert ask(Q.integer(nan)) == False assert ask(Q.rational(nan)) == False assert ask(Q.real(nan)) == False assert ask(Q.extended_real(nan)) == False assert ask(Q.complex(nan)) == False assert ask(Q.irrational(nan)) == False assert ask(Q.imaginary(nan)) == False assert ask(Q.positive(nan)) == False assert ask(Q.nonzero(nan)) == True assert ask(Q.even(nan)) == False assert ask(Q.odd(nan)) == False assert ask(Q.bounded(nan)) == False assert ask(Q.infinitesimal(nan)) == False assert ask(Q.prime(nan)) == False assert ask(Q.composite(nan)) == False
def _eval_refine(self, assumptions): from sympy.assumptions import ask, Q arg = self.args[0] if arg.is_Mul: Ioo = S.ImaginaryUnit * S.Infinity if arg in [Ioo, -Ioo]: return S.NaN coeff = arg.as_coefficient(S.Pi * S.ImaginaryUnit) if coeff: if ask(Q.integer(2 * coeff)): if ask(Q.even(coeff)): return S.One elif ask(Q.odd(coeff)): return S.NegativeOne elif ask(Q.even(coeff + S.Half)): return -S.ImaginaryUnit elif ask(Q.odd(coeff + S.Half)): return S.ImaginaryUnit
def Pow(expr, assumptions): """ Real**Integer -> Real Positive**Real -> Real Real**(Integer/Even) -> Real if base is nonnegative Real**(Integer/Odd) -> Real """ if expr.is_number: return AskRealHandler._number(expr, assumptions) if ask(Q.real(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): return True elif expr.exp.is_Rational: if (expr.exp.q % 2 == 0): return ask(Q.real(expr.base), assumptions) and \ not ask(Q.negative(expr.base), assumptions) else: return True elif ask(Q.real(expr.exp), assumptions): if ask(Q.positive(expr.base), assumptions): return True
def test_even(): x, y, z, t = symbols('x,y,z,t') assert ask(Q.even(x)) == None assert ask(Q.even(x), Q.integer(x)) == None assert ask(Q.even(x), ~Q.integer(x)) == False assert ask(Q.even(x), Q.rational(x)) == None assert ask(Q.even(x), Q.positive(x)) == None assert ask(Q.even(2 * x)) == None assert ask(Q.even(2 * x), Q.integer(x)) == True assert ask(Q.even(2 * x), Q.even(x)) == True assert ask(Q.even(2 * x), Q.irrational(x)) == False assert ask(Q.even(2 * x), Q.odd(x)) == True assert ask(Q.even(2 * x), ~Q.integer(x)) == None assert ask(Q.even(3 * x), Q.integer(x)) == None assert ask(Q.even(3 * x), Q.even(x)) == True assert ask(Q.even(3 * x), Q.odd(x)) == False assert ask(Q.even(x + 1), Q.odd(x)) == True assert ask(Q.even(x + 1), Q.even(x)) == False assert ask(Q.even(x + 2), Q.odd(x)) == False assert ask(Q.even(x + 2), Q.even(x)) == True assert ask(Q.even(7 - x), Q.odd(x)) == True assert ask(Q.even(7 + x), Q.odd(x)) == True assert ask(Q.even(x + y), Q.odd(x) & Q.odd(y)) == True assert ask(Q.even(x + y), Q.odd(x) & Q.even(y)) == False assert ask(Q.even(x + y), Q.even(x) & Q.even(y)) == True assert ask(Q.even(2 * x + 1), Q.integer(x)) == False assert ask(Q.even(2 * x * y), Q.rational(x) & Q.rational(x)) == None assert ask(Q.even(2 * x * y), Q.irrational(x) & Q.irrational(x)) == None assert ask(Q.even(x + y + z), Q.odd(x) & Q.odd(y) & Q.even(z)) == True assert ask(Q.even(x + y + z + t), Q.odd(x) & Q.odd(y) & Q.even(z) & Q.integer(t)) == None assert ask(Q.even(Abs(x)), Q.even(x)) == True assert ask(Q.even(Abs(x)), ~Q.even(x)) == None assert ask(Q.even(re(x)), Q.even(x)) == True assert ask(Q.even(re(x)), ~Q.even(x)) == None assert ask(Q.even(im(x)), Q.even(x)) == True assert ask(Q.even(im(x)), Q.real(x)) == True
def _(expr, assumptions): """ Even * Integer -> Even Even * Odd -> Even Integer * Odd -> ? Odd * Odd -> Odd Even * Even -> Even Integer * Integer -> Even if Integer + Integer = Odd otherwise -> ? """ if expr.is_number: return _EvenPredicate_number(expr, assumptions) even, odd, irrational, acc = False, 0, False, 1 for arg in expr.args: # check for all integers and at least one even if ask(Q.integer(arg), assumptions): if ask(Q.even(arg), assumptions): even = True elif ask(Q.odd(arg), assumptions): odd += 1 elif not even and acc != 1: if ask(Q.odd(acc + arg), assumptions): even = True elif ask(Q.irrational(arg), assumptions): # one irrational makes the result False # two makes it undefined if irrational: break irrational = True else: break acc = arg else: if irrational: return False if even: return True if odd == len(expr.args): return False
def test_rational(): x, y = symbols('x,y') assert ask(Q.rational(x), Q.integer(x)) == True assert ask(Q.rational(x), Q.irrational(x)) == False assert ask(Q.rational(x), Q.real(x)) == None assert ask(Q.rational(x), Q.positive(x)) == None assert ask(Q.rational(x), Q.negative(x)) == None assert ask(Q.rational(x), Q.nonzero(x)) == None assert ask(Q.rational(2 * x), Q.rational(x)) == True assert ask(Q.rational(2 * x), Q.integer(x)) == True assert ask(Q.rational(2 * x), Q.even(x)) == True assert ask(Q.rational(2 * x), Q.odd(x)) == True assert ask(Q.rational(2 * x), Q.irrational(x)) == False assert ask(Q.rational(x / 2), Q.rational(x)) == True assert ask(Q.rational(x / 2), Q.integer(x)) == True assert ask(Q.rational(x / 2), Q.even(x)) == True assert ask(Q.rational(x / 2), Q.odd(x)) == True assert ask(Q.rational(x / 2), Q.irrational(x)) == False assert ask(Q.rational(1 / x), Q.rational(x)) == True assert ask(Q.rational(1 / x), Q.integer(x)) == True assert ask(Q.rational(1 / x), Q.even(x)) == True assert ask(Q.rational(1 / x), Q.odd(x)) == True assert ask(Q.rational(1 / x), Q.irrational(x)) == False assert ask(Q.rational(2 / x), Q.rational(x)) == True assert ask(Q.rational(2 / x), Q.integer(x)) == True assert ask(Q.rational(2 / x), Q.even(x)) == True assert ask(Q.rational(2 / x), Q.odd(x)) == True assert ask(Q.rational(2 / x), Q.irrational(x)) == False # with multiple symbols assert ask(Q.rational(x * y), Q.irrational(x) & Q.irrational(y)) == None assert ask(Q.rational(y / x), Q.rational(x) & Q.rational(y)) == True assert ask(Q.rational(y / x), Q.integer(x) & Q.rational(y)) == True assert ask(Q.rational(y / x), Q.even(x) & Q.rational(y)) == True assert ask(Q.rational(y / x), Q.odd(x) & Q.rational(y)) == True assert ask(Q.rational(y / x), Q.irrational(x) & Q.rational(y)) == False
def Abs(expr, assumptions): return ask(Q.integer(expr.args[0]), assumptions)
def refine_Pow(expr, assumptions): """ Handler for instances of Pow. >>> from sympy import Symbol, Q >>> from sympy.assumptions.refine import refine_Pow >>> from sympy.abc import x,y,z >>> refine_Pow((-1)**x, Q.real(x)) >>> refine_Pow((-1)**x, Q.even(x)) 1 >>> refine_Pow((-1)**x, Q.odd(x)) -1 For powers of -1, even parts of the exponent can be simplified: >>> refine_Pow((-1)**(x+y), Q.even(x)) (-1)**y >>> refine_Pow((-1)**(x+y+z), Q.odd(x) & Q.odd(z)) (-1)**y >>> refine_Pow((-1)**(x+y+2), Q.odd(x)) (-1)**(y + 1) >>> refine_Pow((-1)**(x+3), True) (-1)**(x + 1) """ from sympy.core import Pow, Rational from sympy.functions.elementary.complexes import Abs from sympy.functions import sign if isinstance(expr.base, Abs): if ask(Q.real(expr.base.args[0]), assumptions) and \ ask(Q.even(expr.exp), assumptions): return expr.base.args[0]**expr.exp if ask(Q.real(expr.base), assumptions): if expr.base.is_number: if ask(Q.even(expr.exp), assumptions): return abs(expr.base)**expr.exp if ask(Q.odd(expr.exp), assumptions): return sign(expr.base) * abs(expr.base)**expr.exp if isinstance(expr.exp, Rational): if type(expr.base) is Pow: return abs(expr.base.base)**(expr.base.exp * expr.exp) if expr.base is S.NegativeOne: if expr.exp.is_Add: old = expr # For powers of (-1) we can remove # - even terms # - pairs of odd terms # - a single odd term + 1 # - A numerical constant N can be replaced with mod(N,2) coeff, terms = expr.exp.as_coeff_add() terms = set(terms) even_terms = set([]) odd_terms = set([]) initial_number_of_terms = len(terms) for t in terms: if ask(Q.even(t), assumptions): even_terms.add(t) elif ask(Q.odd(t), assumptions): odd_terms.add(t) terms -= even_terms if len(odd_terms) % 2: terms -= odd_terms new_coeff = (coeff + S.One) % 2 else: terms -= odd_terms new_coeff = coeff % 2 if new_coeff != coeff or len(terms) < initial_number_of_terms: terms.add(new_coeff) expr = expr.base**(Add(*terms)) # Handle (-1)**((-1)**n/2 + m/2) e2 = 2 * expr.exp if ask(Q.even(e2), assumptions): if e2.could_extract_minus_sign(): e2 *= expr.base if e2.is_Add: i, p = e2.as_two_terms() if p.is_Pow and p.base is S.NegativeOne: if ask(Q.integer(p.exp), assumptions): i = (i + 1) / 2 if ask(Q.even(i), assumptions): return expr.base**p.exp elif ask(Q.odd(i), assumptions): return expr.base**(p.exp + 1) else: return expr.base**(p.exp + i) if old != expr: return expr
def _(expr, assumptions): a = expr.exp / I / pi return ask(Q.integer(2 * a) & ~Q.integer(a), assumptions)
def _(expr, assumptions): return ask(Q.integer(expr.exp / I / pi) | Q.real(expr.exp), assumptions)
def _(expr, assumptions): """ * Real**Integer -> Real * Positive**Real -> Real * Real**(Integer/Even) -> Real if base is nonnegative * Real**(Integer/Odd) -> Real * Imaginary**(Integer/Even) -> Real * Imaginary**(Integer/Odd) -> not Real * Imaginary**Real -> ? since Real could be 0 (giving real) or 1 (giving imaginary) * b**Imaginary -> Real if log(b) is imaginary and b != 0 and exponent != integer multiple of I*pi/log(b) * Real**Real -> ? e.g. sqrt(-1) is imaginary and sqrt(2) is not """ if expr.is_number: return _RealPredicate_number(expr, assumptions) if expr.base == E: return ask( Q.integer(expr.exp / I / pi) | Q.real(expr.exp), assumptions) if expr.base.func == exp or (expr.base.is_Pow and expr.base.base == E): if ask(Q.imaginary(expr.base.exp), assumptions): if ask(Q.imaginary(expr.exp), assumptions): return True # If the i = (exp's arg)/(I*pi) is an integer or half-integer # multiple of I*pi then 2*i will be an integer. In addition, # exp(i*I*pi) = (-1)**i so the overall realness of the expr # can be determined by replacing exp(i*I*pi) with (-1)**i. i = expr.base.exp / I / pi if ask(Q.integer(2 * i), assumptions): return ask(Q.real(((-1)**i)**expr.exp), assumptions) return if ask(Q.imaginary(expr.base), assumptions): if ask(Q.integer(expr.exp), assumptions): odd = ask(Q.odd(expr.exp), assumptions) if odd is not None: return not odd return if ask(Q.imaginary(expr.exp), assumptions): imlog = ask(Q.imaginary(log(expr.base)), assumptions) if imlog is not None: # I**i -> real, log(I) is imag; # (2*I)**i -> complex, log(2*I) is not imag return imlog if ask(Q.real(expr.base), assumptions): if ask(Q.real(expr.exp), assumptions): if expr.exp.is_Rational and \ ask(Q.even(expr.exp.q), assumptions): return ask(Q.positive(expr.base), assumptions) elif ask(Q.integer(expr.exp), assumptions): return True elif ask(Q.positive(expr.base), assumptions): return True elif ask(Q.negative(expr.base), assumptions): return False