A system and method for product configuration represents a product using a configuration model having numerical clauses. Features of the product are associated with literals in the numerical clauses. The numerical clauses may specify a number of literals to determine whether the numerical clause is satisfied, satisfiable, or unsatisfiable. Numerical clauses represent constraints that govern the configuration of the product. Resolving numerical clauses and user choices involves one or more inference procedures. In one embodiment, unit clauses represent user choices, and a configuration engine asserts the unit clause and performs numerical unit resolution between the unit clause and all numerical clauses containing the complement (generally a negation) of the unit clause. Complementary literals are eliminated from the current state of the configuration model. In one embodiment, if the uneliminated literals in a numerical clause causes the clause to be satisfied, the uneliminated literals are recursively asserted. The configuration engine then performs numerical unit resolution between the recursively asserted, uneliminated literals and numerical clauses containing the complements of the uneliminated literals. Numerical clauses may also function as literals. Numerical clauses may include negations of consumer literals and positive provider literals. If a user chooses a consumer feature, by knowing the consumer and provider weights, the configuration engine can determine which provider literals should be included, excluded, or remain selectable. Embodiments of the invention can implement a logic-based truth maintenance system and numerical unit resolution.