Technical Report UMIACS--TR--90--54, CS--TR--2454, pages 1-13 pp.. College Park, MD, USA: Maryland Univ., Inst. for Advanced Computer Studies, April 1990.
Abstract: The authors add an extension called debit arcs to place/transition nets. A debit arc allows its destination transition to fire whenever desired, but records a debt (or antitoken) in its source place if a token there is not consumed. A normal token can annihilate with an antitoken. Two natural rules for token/antitoken annihilation (instantaneous, and delayed) are examined. Nets with debit arcs are shown to be a special case of colored nets; under instantaneous annihilation, these nets are equivalent as a class to Turing machines.
Keywords: place/transition net (with) debit arc(s); antitoken; instantaneous, delayed token annihilation; coloured net; Turing machine.