def test_diofantissue_376(): f = symbols('f', cls=Function) e1 = Subs(Derivative(f(x), x), (x, y*z)) e2 = Subs(Derivative(f(t), t), (t, y*z)) assert (x*e1).subs({e2: y}) == x*y e3 = Subs(Derivative(f(t), t), (t, y*z**2)) assert e3.subs({e2: y}) == e3 e4 = Subs(Derivative(f(t), t, t), (t, y*z)) assert e4.subs({e2: y}) == e4
def test_diofantissue_376(): f = symbols('f', cls=Function) e1 = Subs(Derivative(f(x), x), (x, y * z)) e2 = Subs(Derivative(f(t), t), (t, y * z)) assert (x * e1).subs({e2: y}) == x * y e3 = Subs(Derivative(f(t), t), (t, y * z**2)) assert e3.subs({e2: y}) == e3 e4 = Subs(Derivative(f(t), t, t), (t, y * z)) assert e4.subs({e2: y}) == e4
def test_diofantissue_376(): x, y, z, t = symbols('x y z t') f = symbols('f', cls=Function) e1 = Subs(Derivative(f(x), x), x, y * z) e2 = Subs(Derivative(f(t), t), t, y * z) assert (x * e1).subs(e2, y) == x * y e3 = Subs(Derivative(f(t), t), t, y * z**2) assert e3.subs(e2, y) == e3 e4 = Subs(Derivative(f(t), t, t), t, y * z) assert e4.subs(e2, y) == e4