Causal reversibility in concurrent systems means that events that the origin of other events can only be undone after undoing its consequences. In opposition to backtracking, events that are independent of each other can be reversed in an arbitrary order; in other words, we have flexible reversibility with respect to a causality relationship. An implementation of individual token interpretation of Petri Nets (IPNs) has been proposed by Rob Van Glabbeek et al.; the present paper investigates a study of causal reversibility within IPNs. Given N as an IPN, by adding an intuitive firing rule to undo transitions according to the causality relationship, the coherence of N is assured; i.e., the set of all reachable states of N in the reversible ve...