Conway’s game of Life provides interesting problems in which modelling issues in constraint programming can be explored. The problem of finding a maximum density stable pattern (‘still-life’) is discussed. A formulation of this problem as a constraint satisfaction problem with 0-1 variables and non-binary constraints is compared with its dual graph translation into a binary CSP. The success of ...

It is shown that a trivial version of polarization is sufficient to produce separating systems of polynomial invariants: if two points in the direct sum of the G–modules W and m copies of V can be separated by polynomial invariants, then they can be separated by invariants depending only on ≤ 2 dim(V ) variables of type V ; when G is reductive, invariants depending only on ≤ dim(V ) + 1 variabl...

We investigate a mixed 0 − 1 conic quadratic optimization problem with indicator variables arising in mean-risk optimization. The indicator variables are often used to model non-convexities such as fixed charges or cardinality constraints. Observing that the problem reduces to a submodular function minimization for its binary restriction, we derive three classes of strong convex valid inequalit...

We present three new complexity results for classes of planning problems with simple causal graphs. First, we describe a polynomial-time algorithm that uses macros to generate plans for the class 3S of planning problems with binary state variables and acyclic causal graphs. This implies that plan generation may be tractable even when a planning problem has an exponentially long minimal solution...

We present three new complexity results for classes of planning problems with simple causal graphs. First, we describe a polynomial time algorithm that uses macros to generate plans for a class of planning problems with binary state variables and acyclic causal graphs. This implies that plan generation may not be intractable just because a planning problem has exponential length solution. We al...

A pseudo-Boolean function is a real-valued function f(x) = f(x1, x2, . . . , xn) of n binary variables; that is, a mapping from {0, 1}n to R. For a pseudo-Boolean function f(x) on {0, 1}n, we say that g(x, y) is a quadratization of f if g(x, y) is a quadratic polynomial depending on x and on m auxiliary binary variables y1, y2, . . . , ym such that f(x) = min{g(x, y) : y ∈ {0, 1}m} for all x ∈ ...

In this paper it is argued that Hintikka’s game theoretical semantics for Independence Friendly logic does not formalize the intuitions about independent choices; it rather is a formalization of imperfect information. Furthermore it is shown that the logic has several strange properties (e.g. renaming of bound variables is not allowed). An alternative semantics is proposed which formalizes intu...