Abstract: Methods and apparatus are provided for incremental analysis of one or more properties of a program. According to one aspect of the invention, at least one property of a software program is evaluated, given one or more changes to the software program. Nodes in a derivation graph are identified corresponding to changed edges in a control flow graph representation of the software program, wherein the derivation graph describes an earlier evaluation of the software program. In addition, at least one of the identified nodes in the derivation graph is updated and the derivation graph is traversed outward from a location of a change. The revised derivation graph can optionally be further processed to remove false errors.

Abstract: Methods and apparatus are provided for exploring paths through a graph representation of a program or another entity. According to one aspect of the invention, at least one property of a state machine, such as a graph representing a software program, is evaluated. One or more paths in the state machine are evaluated using a state exploration algorithm, wherein the state exploration algorithm maintains a stack data structure representing a current path being processed from an entry state to a current state and a visited state cache indicating zero or more states that have been evaluated. When a state satisfies at least one property, such as having an error, each of the states in the path are removed from the visited states cache if the path satisfies one or more predefined criteria. The one or more predefined criteria may comprise a feasibility of the path.