An r-fold analogue of the positive semidefinite zero forcing process that is carried out on the r-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup when colored with a fractional positive semidefinite forcing set are examined and used to define a three-color forcing game that directly computes the fractional po...

The forcing theorem is the most fundamental result about set forcing, stating that the forcing relation for any set forcing is definable and that the truth lemma holds, that is everything that holds in a generic extension is forced by a condition in the relevant generic filter. We show that both the definability (and, in fact, even the amenability) of the forcing relation and the truth lemma ca...

In this paper we study the notion of forcing for Lukasiewicz predicate logic ( L∀, for short), along the lines of Robinson’s forcing in classical model theory. We deal with both finite and infinite forcing. As regard to the former we prove a Generic Model Theorem for L∀, while for the latter, we study the generic and existentially complete standard models of L∀.

For a connected graph G = (V,E), a set W ⊆ V is called a Steiner set of G if every vertex of G is contained in a Steiner W -tree of G. The Steiner number s(G) of G is the minimum cardinality of its Steiner sets and any Steiner set of cardinality s(G) is a minimum Steiner set of G. For a minimum Steiner set W of G, a subset T ⊆ W is called a forcing subset for W if W is the unique minimum Steine...

In this paper we learn the new idea of forcing total outer independent edge geodetic number a graph. Let G be connected graph and R minimum set G. A subset L ⊆ is known as for if unique containing L. cardinality R. The denoted by (G) = min , where taken over all in Some general properties satisfied concept are studied. It shown that any couple integers l, m with0 < l ≤ − 4, there exists such .

The minimum forcing number of a graph G is the smallest edges simultaneously contained in unique perfect matching G. Zhang et al. (2010) claimed that any fullerene was bounded below by 3. However, we find there exists exactly one exceptional F24 with 2. In this paper, characterize all fullerenes 3 construction approach. This also solves an open problem proposed We except for F24, anti-forcing 4...

If κ < λ are such that κ is a strong cardinal whose strongness is indestructible under κ-strategically closed forcing and λ is weakly compact, then we show that A = {δ < κ | δ is a non-weakly compact Mahlo cardinal which reflects stationary sets} must be unbounded in κ. This phenomenon, however, need not occur in a universe with relatively few large cardinals. In particular, we show how to cons...