Isn't that a different definition of 2 and 4 than he was using? They're taking 2 and 4 to be complex numbers (2 + 0i), where as he was taking 2 to be a cardina

Isn't that a different definition of 2 and 4 than he was using? They're taking 2 and 4 to be complex numbers (2 + 0i), where as he was taking 2 to be a cardinal number.