SymPy Gamma

Input:

simplify%28cos%28x%29cos%28y%29 - sin%28x%29sin%28y%29%29

Error:

simplify%28cos%28x%29cos%28y%29 - sin%28x%29sin%28y%29%29

unsupported operand type(s) for %: 'function' and 'Integer'

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