Second-Order Logic and Fagin`s Theorem
... Corollary 7.10 Every polynomial-time query is expressible as a second-order, existential Horn formula: P ⊆ SO∃-Horn. The proof of Theorem 7.8 shows that nondeterministic time nk is contained in (SO∃, arity 2k). Lynch improved this to arity k. His proof uses the numeric predicate PLUS. Fagin’s theore ...
... Corollary 7.10 Every polynomial-time query is expressible as a second-order, existential Horn formula: P ⊆ SO∃-Horn. The proof of Theorem 7.8 shows that nondeterministic time nk is contained in (SO∃, arity 2k). Lynch improved this to arity k. His proof uses the numeric predicate PLUS. Fagin’s theore ...
Lecture notes #2 - inst.eecs.berkeley.edu
... sequence of statements, ending with the proposition being proved, with the property that each statement is either an axiom or its truth follows easily from the fact that the previous statements are true. For example, in high school geometry you may have written two-column proofs where one column lis ...
... sequence of statements, ending with the proposition being proved, with the property that each statement is either an axiom or its truth follows easily from the fact that the previous statements are true. For example, in high school geometry you may have written two-column proofs where one column lis ...
3.3 Inference
... We then used the definition of even numbers, and our previous parenthetic comment suggests that it was natural for us to use the definition symbolically. The definition tells us that if m is an even number, then there exists another integer i such that m = 2i. We combined this with the assumption that ...
... We then used the definition of even numbers, and our previous parenthetic comment suggests that it was natural for us to use the definition symbolically. The definition tells us that if m is an even number, then there exists another integer i such that m = 2i. We combined this with the assumption that ...