Title :
Resolution lower bounds for perfect matching principles
Author :
Razborov, Alexander A.
Author_Institution :
Inst. for Adv. Study, Princeton, NJ, USA
fDate :
6/24/1905 12:00:00 AM
Abstract :
For an arbitrary hypergraph H let PM(H) be the propositional formula asserting that H contains a perfect matching. We show that every resolution refutation of PM(H) must have size exp((Ω(δ(H)/λ(H)r(H)(log n(H))(r(H)+log n(H)))), where n(H) is the number of vertices, δ(H) is the minimal degree of a vertex, r(H) is the maximal size of an edge, and λ(H) is the maximal number of edges incident to two different vertices. For ordinary graphs G our general bound considerably simplifies to exp (Ω(δ(G)/(log n(G))2))). As a direct corollary, every resolution proof of the functional onto a version of the pigeonhole principle onto - FPHPnm must have size exp (Ω(n/(log m)2)) (which becomes exp (Ω(n1/3)) when the number of pigeons m is unbounded). This in turn immediately implies an exp(Ω(t/n3)) lower bound on the size of resolution proofs of the principle circuitt (fn) asserting that the circuit size of the Boolean function fn in n variables is greater than t. In particular resolution does not possess efficient proofs of NP ≡ P/poly. These results relativize, in a natural way, to more general principle M(U|H) asserting that H contains a matching covering all vertices in U ⊆ V(H)
Keywords :
Boolean functions; circuit complexity; graph theory; logic circuits; Boolean circuits; Boolean function; arbitrary hypergraph; general bound; perfect matching principles; pigeonhole principle; propositional formula; propositional proof complexity; resolution lower bounds; resolution proofs; Bipartite graph; Boolean functions; Circuits; Computational complexity; Robustness;
Conference_Titel :
Computational Complexity, 2002. Proceedings. 17th IEEE Annual Conference on
Conference_Location :
Montreal, Que.
Print_ISBN :
0-7695-1468-5
DOI :
10.1109/CCC.2002.1004336