Lovász Extension Convexity Criterion Combinatorics Decidability of Propositional LK and LJ Derivability Logic Edmonds Matching Polytope Theorem Combinatorics Replacement in Forcing Extensions Set Theory Colorful Caratheodory Theorem Combinatorics Decidability of Propositional Validity Logic Associativity of Ordinal Multiplication Logic Separation in a Forcing Extension Set Theory Discrete Mathematics Area