Circuit element type Nullator.
A nullator is an ideal two-terminal circuit element which enforces both a zero voltage and a zero current between its terminals. It is thus neither a voltage nor a current source but rather both at the same time. The value specification in the netlist entry of a nullator is irrelevant and should be set to 0 (zero). Note that an element with a arbitrary but fixed branch current and branch voltage is also known as a fixator. With a zero current and voltage, a nullator is a special case of a fixator. A nullator usually appears paired with a norator, thus forming a nullor. A nullor represents a controlled source of arbitrary type with infinite gain, such as an ideal operational amplifier.