Why Is Every Synapomorphy Also An Symplesiomorphy?

Why Is Every Synapomorphy Also An Symplesiomorphy? An same as autapomorphy is a derived trait that is unique to one group, while a same as synapomorphy is a derived trait shared by two or more groups. A same as symplesiomorphy is similarly a shared primitive trait. This means that a trait can be a synapomorphy