The output characteristics also make the AD590 easy to multiplex: the current can be switched by a CMOS multiplexer or the supply voltage can be switched by a logic gateoutput.
To convert a gate circuit to a Boolean expression, label each gateoutput with a Boolean sub-expression corresponding to the gates' input signals, until a final expression is reached at the last gate.
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.