T20 - Reserved Node

The T20 - Reserved Node is a node restricted to specific models of the Tessellated Intelligence System. Documentation for this node type is distributed only with systems containing the node type. Unauthorized requests for domination describing this node are reported to the state security bureau as required by law. No other information on this node type has been obtained.
The node has the following specification as emulated by one of the TIS-NET Nexuses (Specifically the 22.280.8: T20 Node Emulator):
Read in an instruction as a number 0-4.
If 0, read in a value and store it as P.
If 1, read in a value and store it as Q.
If 2, swap values P and Q.
If 3, add Q to P.
If 4, output P.