from sympy import (
    symbols, sin, simplify, cos, trigsimp, tan, exptrigsimp,sinh,
    cosh, diff, cot, Subs, exp, tanh, S, integrate, I,Matrix,
    Symbol, coth, pi, log, count_ops, sqrt, E, expand, Piecewise , Rational
    )

from sympy.testing.pytest import XFAIL

from sympy.abc import x, y



def test_trigsimp1():
    x, y = symbols('x,y')

    assert trigsimp(1 - sin(x)**2) == cos(x)**2
    assert trigsimp(1 - cos(x)**2) == sin(x)**2
    assert trigsimp(sin(x)**2 + cos(x)**2) == 1
    assert trigsimp(1 + tan(x)**2) == 1/cos(x)**2
    assert trigsimp(1/cos(x)**2 - 1) == tan(x)**2
    assert trigsimp(1/cos(x)**2 - tan(x)**2) == 1
    assert trigsimp(1 + cot(x)**2) == 1/sin(x)**2
    assert trigsimp(1/sin(x)**2 - 1) == 1/tan(x)**2
    assert trigsimp(1/sin(x)**2 - cot(x)**2) == 1

    assert trigsimp(5*cos(x)**2 + 5*sin(x)**2) == 5
    assert trigsimp(5*cos(x/2)**2 + 2*sin(x/2)**2) == 3*cos(x)/2 + Rational(7, 2)

    assert trigsimp(sin(x)/cos(x)) == tan(x)
    assert trigsimp(2*tan(x)*cos(x)) == 2*sin(x)
    assert trigsimp(cot(x)**3*sin(x)**3) == cos(x)**3
    assert trigsimp(y*tan(x)**2/sin(x)**2) == y/cos(x)**2
    assert trigsimp(cot(x)/cos(x)) == 1/sin(x)

    assert trigsimp(sin(x + y) + sin(x - y)) == 2*sin(x)*cos(y)
    assert trigsimp(sin(x + y) - sin(x - y)) == 2*sin(y)*cos(x)
    assert trigsimp(cos(x + y) + cos(x - y)) == 2*cos(x)*cos(y)
    assert trigsimp(cos(x + y) - cos(x - y)) == -2*sin(x)*sin(y)
    assert trigsimp(tan(x + y) - tan(x)/(1 - tan(x)*tan(y))) == \
        sin(y)/(-sin(y)*tan(x) + cos(y))  # -tan(y)/(tan(x)*tan(y) - 1)

    assert trigsimp(sinh(x + y) + sinh(x - y)) == 2*sinh(x)*cosh(y)
    assert trigsimp(sinh(x + y) - sinh(x - y)) == 2*sinh(y)*cosh(x)
    assert trigsimp(cosh(x + y) + cosh(x - y)) == 2*cosh(x)*cosh(y)
    assert trigsimp(cosh(x + y) - cosh(x - y)) == 2*sinh(x)*sinh(y)
    assert trigsimp(tanh(x + y) - tanh(x)/(1 + tanh(x)*tanh(y))) == \
        sinh(y)/(sinh(y)*tanh(x) + cosh(y))

    assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2) == 1
    e = 2*sin(x)**2 + 2*cos(x)**2
    assert trigsimp(log(e)) == log(2)


def test_trigsimp1a():
    assert trigsimp(sin(2)**2*cos(3)*exp(2)/cos(2)**2) == tan(2)**2*cos(3)*exp(2)
    assert trigsimp(tan(2)**2*cos(3)*exp(2)*cos(2)**2) == sin(2)**2*cos(3)*exp(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)*sin(2)) == cos(3)*exp(2)*cos(2)
    assert trigsimp(tan(2)*cos(3)*exp(2)/sin(2)) == cos(3)*exp(2)/cos(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)/cos(2)) == cos(3)*exp(2)/sin(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)*tan(2)) == cos(3)*exp(2)
    assert trigsimp(sinh(2)*cos(3)*exp(2)/cosh(2)) == tanh(2)*cos(3)*exp(2)
    assert trigsimp(tanh(2)*cos(3)*exp(2)*cosh(2)) == sinh(2)*cos(3)*exp(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)*sinh(2)) == cosh(2)*cos(3)*exp(2)
    assert trigsimp(tanh(2)*cos(3)*exp(2)/sinh(2)) == cos(3)*exp(2)/cosh(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)/cosh(2)) == cos(3)*exp(2)/sinh(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)*tanh(2)) == cos(3)*exp(2)


def test_trigsimp2():
    x, y = symbols('x,y')
    assert trigsimp(cos(x)**2*sin(y)**2 + cos(x)**2*cos(y)**2 + sin(x)**2,
            recursive=True) == 1
    assert trigsimp(sin(x)**2*sin(y)**2 + sin(x)**2*cos(y)**2 + cos(x)**2,
            recursive=True) == 1
    assert trigsimp(
        Subs(x, x, sin(y)**2 + cos(y)**2)) == Subs(x, x, 1)


def test_issue_4373():
    x = Symbol("x")
    assert abs(trigsimp(2.0*sin(x)**2 + 2.0*cos(x)**2) - 2.0) < 1e-10


def test_trigsimp3():
    x, y = symbols('x,y')
    assert trigsimp(sin(x)/cos(x)) == tan(x)
    assert trigsimp(sin(x)**2/cos(x)**2) == tan(x)**2
    assert trigsimp(sin(x)**3/cos(x)**3) == tan(x)**3
    assert trigsimp(sin(x)**10/cos(x)**10) == tan(x)**10

    assert trigsimp(cos(x)/sin(x)) == 1/tan(x)
    assert trigsimp(cos(x)**2/sin(x)**2) == 1/tan(x)**2
    assert trigsimp(cos(x)**10/sin(x)**10) == 1/tan(x)**10

    assert trigsimp(tan(x)) == trigsimp(sin(x)/cos(x))


def test_issue_4661():
    a, x, y = symbols('a x y')
    eq = -4*sin(x)**4 + 4*cos(x)**4 - 8*cos(x)**2
    assert trigsimp(eq) == -4
    n = sin(x)**6 + 4*sin(x)**4*cos(x)**2 + 5*sin(x)**2*cos(x)**4 + 2*cos(x)**6
    d = -sin(x)**2 - 2*cos(x)**2
    assert simplify(n/d) == -1
    assert trigsimp(-2*cos(x)**2 + cos(x)**4 - sin(x)**4) == -1
    eq = (- sin(x)**3/4)*cos(x) + (cos(x)**3/4)*sin(x) - sin(2*x)*cos(2*x)/8
    assert trigsimp(eq) == 0


def test_issue_4494():
    a, b = symbols('a b')
    eq = sin(a)**2*sin(b)**2 + cos(a)**2*cos(b)**2*tan(a)**2 + cos(a)**2
    assert trigsimp(eq) == 1


def test_issue_5948():
    a, x, y = symbols('a x y')
    assert trigsimp(diff(integrate(cos(x)/sin(x)**7, x), x)) == \
           cos(x)/sin(x)**7


def test_issue_4775():
    a, x, y = symbols('a x y')
    assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)) == sin(x + y)
    assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)+3) == sin(x + y) + 3


def test_issue_4280():
    a, x, y = symbols('a x y')
    assert trigsimp(cos(x)**2 + cos(y)**2*sin(x)**2 + sin(y)**2*sin(x)**2) == 1
    assert trigsimp(a**2*sin(x)**2 + a**2*cos(y)**2*cos(x)**2 + a**2*cos(x)**2*sin(y)**2) == a**2
    assert trigsimp(a**2*cos(y)**2*sin(x)**2 + a**2*sin(y)**2*sin(x)**2) == a**2*sin(x)**2


def test_issue_3210():
    eqs = (sin(2)*cos(3) + sin(3)*cos(2),
        -sin(2)*sin(3) + cos(2)*cos(3),
        sin(2)*cos(3) - sin(3)*cos(2),
        sin(2)*sin(3) + cos(2)*cos(3),
        sin(2)*sin(3) + cos(2)*cos(3) + cos(2),
        sinh(2)*cosh(3) + sinh(3)*cosh(2),
        sinh(2)*sinh(3) + cosh(2)*cosh(3),
        )
    assert [trigsimp(e) for e in eqs] == [
        sin(5),
        cos(5),
        -sin(1),
        cos(1),
        cos(1) + cos(2),
        sinh(5),
        cosh(5),
        ]


def test_trigsimp_issues():
    a, x, y = symbols('a x y')

    # issue 4625 - factor_terms works, too
    assert trigsimp(sin(x)**3 + cos(x)**2*sin(x)) == sin(x)

    # issue 5948
    assert trigsimp(diff(integrate(cos(x)/sin(x)**3, x), x)) == \
        cos(x)/sin(x)**3
    assert trigsimp(diff(integrate(sin(x)/cos(x)**3, x), x)) == \
        sin(x)/cos(x)**3

    # check integer exponents
    e = sin(x)**y/cos(x)**y
    assert trigsimp(e) == e
    assert trigsimp(e.subs(y, 2)) == tan(x)**2
    assert trigsimp(e.subs(x, 1)) == tan(1)**y

    # check for multiple patterns
    assert (cos(x)**2/sin(x)**2*cos(y)**2/sin(y)**2).trigsimp() == \
        1/tan(x)**2/tan(y)**2
    assert trigsimp(cos(x)/sin(x)*cos(x+y)/sin(x+y)) == \
        1/(tan(x)*tan(x + y))

    eq = cos(2)*(cos(3) + 1)**2/(cos(3) - 1)**2
    assert trigsimp(eq) == eq.factor()  # factor makes denom (-1 + cos(3))**2
    assert trigsimp(cos(2)*(cos(3) + 1)**2*(cos(3) - 1)**2) == \
        cos(2)*sin(3)**4

    # issue 6789; this generates an expression that formerly caused
    # trigsimp to hang
    assert cot(x).equals(tan(x)) is False

    # nan or the unchanged expression is ok, but not sin(1)
    z = cos(x)**2 + sin(x)**2 - 1
    z1 = tan(x)**2 - 1/cot(x)**2
    n = (1 + z1/z)
    assert trigsimp(sin(n)) != sin(1)
    eq = x*(n - 1) - x*n
    assert trigsimp(eq) is S.NaN
    assert trigsimp(eq, recursive=True) is S.NaN
    assert trigsimp(1).is_Integer

    assert trigsimp(-sin(x)**4 - 2*sin(x)**2*cos(x)**2 - cos(x)**4) == -1


def test_trigsimp_issue_2515():
    x = Symbol('x')
    assert trigsimp(x*cos(x)*tan(x)) == x*sin(x)
    assert trigsimp(-sin(x) + cos(x)*tan(x)) == 0


def test_trigsimp_issue_3826():
    assert trigsimp(tan(2*x).expand(trig=True)) == tan(2*x)


def test_trigsimp_issue_4032():
    n = Symbol('n', integer=True, positive=True)
    assert trigsimp(2**(n/2)*cos(pi*n/4)/2 + 2**(n - 1)/2) == \
        2**(n/2)*cos(pi*n/4)/2 + 2**n/4


def test_trigsimp_issue_7761():
    assert trigsimp(cosh(pi/4)) == cosh(pi/4)


def test_trigsimp_noncommutative():
    x, y = symbols('x,y')
    A, B = symbols('A,B', commutative=False)

    assert trigsimp(A - A*sin(x)**2) == A*cos(x)**2
    assert trigsimp(A - A*cos(x)**2) == A*sin(x)**2
    assert trigsimp(A*sin(x)**2 + A*cos(x)**2) == A
    assert trigsimp(A + A*tan(x)**2) == A/cos(x)**2
    assert trigsimp(A/cos(x)**2 - A) == A*tan(x)**2
    assert trigsimp(A/cos(x)**2 - A*tan(x)**2) == A
    assert trigsimp(A + A*cot(x)**2) == A/sin(x)**2
    assert trigsimp(A/sin(x)**2 - A) == A/tan(x)**2
    assert trigsimp(A/sin(x)**2 - A*cot(x)**2) == A

    assert trigsimp(y*A*cos(x)**2 + y*A*sin(x)**2) == y*A

    assert trigsimp(A*sin(x)/cos(x)) == A*tan(x)
    assert trigsimp(A*tan(x)*cos(x)) == A*sin(x)
    assert trigsimp(A*cot(x)**3*sin(x)**3) == A*cos(x)**3
    assert trigsimp(y*A*tan(x)**2/sin(x)**2) == y*A/cos(x)**2
    assert trigsimp(A*cot(x)/cos(x)) == A/sin(x)

    assert trigsimp(A*sin(x + y) + A*sin(x - y)) == 2*A*sin(x)*cos(y)
    assert trigsimp(A*sin(x + y) - A*sin(x - y)) == 2*A*sin(y)*cos(x)
    assert trigsimp(A*cos(x + y) + A*cos(x - y)) == 2*A*cos(x)*cos(y)
    assert trigsimp(A*cos(x + y) - A*cos(x - y)) == -2*A*sin(x)*sin(y)

    assert trigsimp(A*sinh(x + y) + A*sinh(x - y)) == 2*A*sinh(x)*cosh(y)
    assert trigsimp(A*sinh(x + y) - A*sinh(x - y)) == 2*A*sinh(y)*cosh(x)
    assert trigsimp(A*cosh(x + y) + A*cosh(x - y)) == 2*A*cosh(x)*cosh(y)
    assert trigsimp(A*cosh(x + y) - A*cosh(x - y)) == 2*A*sinh(x)*sinh(y)

    assert trigsimp(A*cos(0.12345)**2 + A*sin(0.12345)**2) == 1.0*A


def test_hyperbolic_simp():
    x, y = symbols('x,y')

    assert trigsimp(sinh(x)**2 + 1) == cosh(x)**2
    assert trigsimp(cosh(x)**2 - 1) == sinh(x)**2
    assert trigsimp(cosh(x)**2 - sinh(x)**2) == 1
    assert trigsimp(1 - tanh(x)**2) == 1/cosh(x)**2
    assert trigsimp(1 - 1/cosh(x)**2) == tanh(x)**2
    assert trigsimp(tanh(x)**2 + 1/cosh(x)**2) == 1
    assert trigsimp(coth(x)**2 - 1) == 1/sinh(x)**2
    assert trigsimp(1/sinh(x)**2 + 1) == 1/tanh(x)**2
    assert trigsimp(coth(x)**2 - 1/sinh(x)**2) == 1

    assert trigsimp(5*cosh(x)**2 - 5*sinh(x)**2) == 5
    assert trigsimp(5*cosh(x/2)**2 - 2*sinh(x/2)**2) == 3*cosh(x)/2 + Rational(7, 2)

    assert trigsimp(sinh(x)/cosh(x)) == tanh(x)
    assert trigsimp(tanh(x)) == trigsimp(sinh(x)/cosh(x))
    assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
    assert trigsimp(2*tanh(x)*cosh(x)) == 2*sinh(x)
    assert trigsimp(coth(x)**3*sinh(x)**3) == cosh(x)**3
    assert trigsimp(y*tanh(x)**2/sinh(x)**2) == y/cosh(x)**2
    assert trigsimp(coth(x)/cosh(x)) == 1/sinh(x)

    for a in (pi/6*I, pi/4*I, pi/3*I):
        assert trigsimp(sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x + a)
        assert trigsimp(-sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x - a)

    e = 2*cosh(x)**2 - 2*sinh(x)**2
    assert trigsimp(log(e)) == log(2)

    # issue 19535:
    assert trigsimp(sqrt(cosh(x)**2 - 1)) == sqrt(sinh(x)**2)

    assert trigsimp(cosh(x)**2*cosh(y)**2 - cosh(x)**2*sinh(y)**2 - sinh(x)**2,
            recursive=True) == 1
    assert trigsimp(sinh(x)**2*sinh(y)**2 - sinh(x)**2*cosh(y)**2 + cosh(x)**2,
            recursive=True) == 1

    assert abs(trigsimp(2.0*cosh(x)**2 - 2.0*sinh(x)**2) - 2.0) < 1e-10

    assert trigsimp(sinh(x)**2/cosh(x)**2) == tanh(x)**2
    assert trigsimp(sinh(x)**3/cosh(x)**3) == tanh(x)**3
    assert trigsimp(sinh(x)**10/cosh(x)**10) == tanh(x)**10
    assert trigsimp(cosh(x)**3/sinh(x)**3) == 1/tanh(x)**3

    assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
    assert trigsimp(cosh(x)**2/sinh(x)**2) == 1/tanh(x)**2
    assert trigsimp(cosh(x)**10/sinh(x)**10) == 1/tanh(x)**10

    assert trigsimp(x*cosh(x)*tanh(x)) == x*sinh(x)
    assert trigsimp(-sinh(x) + cosh(x)*tanh(x)) == 0

    assert tan(x) != 1/cot(x)  # cot doesn't auto-simplify

    assert trigsimp(tan(x) - 1/cot(x)) == 0
    assert trigsimp(3*tanh(x)**7 - 2/coth(x)**7) == tanh(x)**7


def test_trigsimp_groebner():
    from sympy.simplify.trigsimp import trigsimp_groebner

    c = cos(x)
    s = sin(x)
    ex = (4*s*c + 12*s + 5*c**3 + 21*c**2 + 23*c + 15)/(
        -s*c**2 + 2*s*c + 15*s + 7*c**3 + 31*c**2 + 37*c + 21)
    resnum = (5*s - 5*c + 1)
    resdenom = (8*s - 6*c)
    results = [resnum/resdenom, (-resnum)/(-resdenom)]
    assert trigsimp_groebner(ex) in results
    assert trigsimp_groebner(s/c, hints=[tan]) == tan(x)
    assert trigsimp_groebner(c*s) == c*s
    assert trigsimp((-s + 1)/c + c/(-s + 1),
                    method='groebner') == 2/c
    assert trigsimp((-s + 1)/c + c/(-s + 1),
                    method='groebner', polynomial=True) == 2/c

    # Test quick=False works
    assert trigsimp_groebner(ex, hints=[2]) in results
    assert trigsimp_groebner(ex, hints=[int(2)]) in results

    # test "I"
    assert trigsimp_groebner(sin(I*x)/cos(I*x), hints=[tanh]) == I*tanh(x)

    # test hyperbolic / sums
    assert trigsimp_groebner((tanh(x)+tanh(y))/(1+tanh(x)*tanh(y)),
                             hints=[(tanh, x, y)]) == tanh(x + y)


def test_issue_2827_trigsimp_methods():
    measure1 = lambda expr: len(str(expr))
    measure2 = lambda expr: -count_ops(expr)
                                       # Return the most complicated result
    expr = (x + 1)/(x + sin(x)**2 + cos(x)**2)
    ans = Matrix([1])
    M = Matrix([expr])
    assert trigsimp(M, method='fu', measure=measure1) == ans
    assert trigsimp(M, method='fu', measure=measure2) != ans
    # all methods should work with Basic expressions even if they
    # aren't Expr
    M = Matrix.eye(1)
    assert all(trigsimp(M, method=m) == M for m in
        'fu matching groebner old'.split())
    # watch for E in exptrigsimp, not only exp()
    eq = 1/sqrt(E) + E
    assert exptrigsimp(eq) == eq

def test_issue_15129_trigsimp_methods():
    t1 = Matrix([sin(Rational(1, 50)), cos(Rational(1, 50)), 0])
    t2 = Matrix([sin(Rational(1, 25)), cos(Rational(1, 25)), 0])
    t3 = Matrix([cos(Rational(1, 25)), sin(Rational(1, 25)), 0])
    r1 = t1.dot(t2)
    r2 = t1.dot(t3)
    assert trigsimp(r1) == cos(Rational(1, 50))
    assert trigsimp(r2) == sin(Rational(3, 50))

def test_exptrigsimp():
    def valid(a, b):
        from sympy.testing.randtest import verify_numerically as tn
        if not (tn(a, b) and a == b):
            return False
        return True

    assert exptrigsimp(exp(x) + exp(-x)) == 2*cosh(x)
    assert exptrigsimp(exp(x) - exp(-x)) == 2*sinh(x)
    assert exptrigsimp((2*exp(x)-2*exp(-x))/(exp(x)+exp(-x))) == 2*tanh(x)
    assert exptrigsimp((2*exp(2*x)-2)/(exp(2*x)+1)) == 2*tanh(x)
    e = [cos(x) + I*sin(x), cos(x) - I*sin(x),
         cosh(x) - sinh(x), cosh(x) + sinh(x)]
    ok = [exp(I*x), exp(-I*x), exp(-x), exp(x)]
    assert all(valid(i, j) for i, j in zip(
        [exptrigsimp(ei) for ei in e], ok))

    ue = [cos(x) + sin(x), cos(x) - sin(x),
          cosh(x) + I*sinh(x), cosh(x) - I*sinh(x)]
    assert [exptrigsimp(ei) == ei for ei in ue]

    res = []
    ok = [y*tanh(1), 1/(y*tanh(1)), I*y*tan(1), -I/(y*tan(1)),
        y*tanh(x), 1/(y*tanh(x)), I*y*tan(x), -I/(y*tan(x)),
        y*tanh(1 + I), 1/(y*tanh(1 + I))]
    for a in (1, I, x, I*x, 1 + I):
        w = exp(a)
        eq = y*(w - 1/w)/(w + 1/w)
        res.append(simplify(eq))
        res.append(simplify(1/eq))
    assert all(valid(i, j) for i, j in zip(res, ok))

    for a in range(1, 3):
        w = exp(a)
        e = w + 1/w
        s = simplify(e)
        assert s == exptrigsimp(e)
        assert valid(s, 2*cosh(a))
        e = w - 1/w
        s = simplify(e)
        assert s == exptrigsimp(e)
        assert valid(s, 2*sinh(a))

def test_exptrigsimp_noncommutative():
    a,b = symbols('a b', commutative=False)
    x = Symbol('x', commutative=True)
    assert exp(a + x) == exptrigsimp(exp(a)*exp(x))
    p = exp(a)*exp(b) - exp(b)*exp(a)
    assert p == exptrigsimp(p) != 0

def test_powsimp_on_numbers():
    assert 2**(Rational(1, 3) - 2) == 2**Rational(1, 3)/4


@XFAIL
def test_issue_6811_fail():
    # from doc/src/modules/physics/mechanics/examples.rst, the current `eq`
    # at Line 576 (in different variables) was formerly the equivalent and
    # shorter expression given below...it would be nice to get the short one
    # back again
    xp, y, x, z = symbols('xp, y, x, z')
    eq = 4*(-19*sin(x)*y + 5*sin(3*x)*y + 15*cos(2*x)*z - 21*z)*xp/(9*cos(x) - 5*cos(3*x))
    assert trigsimp(eq) == -2*(2*cos(x)*tan(x)*y + 3*z)*xp/cos(x)


def test_Piecewise():
    e1 = x*(x + y) - y*(x + y)
    e2 = sin(x)**2 + cos(x)**2
    e3 = expand((x + y)*y/x)
    # s1 = simplify(e1)
    s2 = simplify(e2)
    # s3 = simplify(e3)

    # trigsimp tries not to touch non-trig containing args
    assert trigsimp(Piecewise((e1, e3 < e2), (e3, True))) == \
        Piecewise((e1, e3 < s2), (e3, True))

def test_trigsimp_old():
    x, y = symbols('x,y')

    assert trigsimp(1 - sin(x)**2, old=True) == cos(x)**2
    assert trigsimp(1 - cos(x)**2, old=True) == sin(x)**2
    assert trigsimp(sin(x)**2 + cos(x)**2, old=True) == 1
    assert trigsimp(1 + tan(x)**2, old=True) == 1/cos(x)**2
    assert trigsimp(1/cos(x)**2 - 1, old=True) == tan(x)**2
    assert trigsimp(1/cos(x)**2 - tan(x)**2, old=True) == 1
    assert trigsimp(1 + cot(x)**2, old=True) == 1/sin(x)**2
    assert trigsimp(1/sin(x)**2 - cot(x)**2, old=True) == 1

    assert trigsimp(5*cos(x)**2 + 5*sin(x)**2, old=True) == 5

    assert trigsimp(sin(x)/cos(x), old=True) == tan(x)
    assert trigsimp(2*tan(x)*cos(x), old=True) == 2*sin(x)
    assert trigsimp(cot(x)**3*sin(x)**3, old=True) == cos(x)**3
    assert trigsimp(y*tan(x)**2/sin(x)**2, old=True) == y/cos(x)**2
    assert trigsimp(cot(x)/cos(x), old=True) == 1/sin(x)

    assert trigsimp(sin(x + y) + sin(x - y), old=True) == 2*sin(x)*cos(y)
    assert trigsimp(sin(x + y) - sin(x - y), old=True) == 2*sin(y)*cos(x)
    assert trigsimp(cos(x + y) + cos(x - y), old=True) == 2*cos(x)*cos(y)
    assert trigsimp(cos(x + y) - cos(x - y), old=True) == -2*sin(x)*sin(y)

    assert trigsimp(sinh(x + y) + sinh(x - y), old=True) == 2*sinh(x)*cosh(y)
    assert trigsimp(sinh(x + y) - sinh(x - y), old=True) == 2*sinh(y)*cosh(x)
    assert trigsimp(cosh(x + y) + cosh(x - y), old=True) == 2*cosh(x)*cosh(y)
    assert trigsimp(cosh(x + y) - cosh(x - y), old=True) == 2*sinh(x)*sinh(y)

    assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2, old=True) == 1

    assert trigsimp(sin(x)/cos(x), old=True, method='combined') == tan(x)
    assert trigsimp(sin(x)/cos(x), old=True, method='groebner') == sin(x)/cos(x)
    assert trigsimp(sin(x)/cos(x), old=True, method='groebner', hints=[tan]) == tan(x)

    assert trigsimp(1-sin(sin(x)**2+cos(x)**2)**2, old=True, deep=True) == cos(1)**2
