Powers of rectangular and exponential form of complex numbers are not equivalent for simplify

[ghost]

Hi! This code

import sympy as sym
sym.init_printing()
n = sym.symbols('n', integer=True)
a = sym.I**n
b = sym.E**(sym.I * sym.pi / 2 * n)
sym.simplify(a - b)

outputs

.

However, I would expect it to do the simplification and return instead.

Note that when is a constant instead of a symbol, it works:

import sympy as sym
sym.init_printing()
n = 2
a = sym.I**n
b = sym.E**(sym.I * sym.pi / 2 * n)
sym.simplify(a - b)

outputs

.

[sidhantnagpal]

A workaround could be to use a.rewrite(exp) - b.