In tests, they modeled a DNA version of an XOR logic gate that generates an output when one of two inputs is present, but not when both or neither is present.
Portal: A permanent Gate, allowing access to or from (not always both) a particular location.
传送门： 一道永久存在的门径，允许人来往于某个特定地点。
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You shall take both of them to the gate of that town and stone them to death — the girl because she was in a town and did not scream for help, and the man because he violated another man's wife.