Patent ID: 6877141

Claim:
A method for evaluating a validation vector, comprising: receiving a network comprising a plurality of nodes, the network associated with a target set comprising one or more nodes of the plurality of nodes; repeating the following until the one or more nodes of the target set have been selected to yield one or more validation vectors: selecting a node from the target set; assigning a tag of a plurality of tags to the node, the tag representing an error of a current value of a variable corresponding to the node, the plurality of tags comprising: a positive tag indicating that a correct value of the variable is greater than the current value; a negative tag indicating that the correct value of the variable is less than the current value; an unsigned tag indicating that the correct value of the variable is different from the current value, and the sign of the error is unknown; and an unknown tag indicating that it is unclear whether the correct value of the variable is different from the current value, the unsigned tag distinct from the unknown tag; generating a test environment specifying a propagation path from an input, through the node, and to an output; translating the test environment into a validation vector; and propagating the tag to the output according to the validation vector; and determining coverage for the one or more validation vectors in accordance with the propagation to evaluate the one or more validation vectors.