B. Parallel graph-matching algorithm The basic methodology proposed by Shen and Tsai is based on generate and test mechanism. Generation of state space nodes expands the state space and incurs computation time as successive nodes are generated and the associated costs are computed. The parallel graph matching algorithm parallizes the generate mechanism, thus dividing the state space into several smaller state-spaces. The basic steps involved are as follows:- Let N be the number of parallel graph matching tasks. Let T = (VT' ET) represent the task graph, P = (Vp, Ep) represent the processor graph. Let Pi = (Vpi, Epi )be a sub graph of P, which is used by the ith task for mapping. The number of sub graphs of P is assumed to be equal to the number of parallel graph matching tasks. Each graph-matching task is assumed to follow the steps 1 to 5 as in [3] for finding an optimal weak homomorphism between two graphs, the only difference being the fact that the node for expansion is the one