Cold Gas in Cluster Cores

I review the literature's census of the cold gas in clusters of galaxies. Cold gas here is defined as the gas that is cooler than X-ray emitting temperatures (~10^7 K) and is not in stars. I present new Spitzer IRAC and MIPS observations of Abell 2597 (PI: Sparks) that reveal significant amounts of warm dust and star formation at the level of 5 solar masses per year. This rate is inconsistent with the mass cooling rate of 20 +/- 5 solar masses per year inferred from a FUSE [OVI] detection.Comment: 10 pages, conference proceeding

PTTP+GLiDeS: Guiding Linear Deductions with Semantics

This paper describes PTTP+GLiDeS, a PTTP style prover augmented with a semantic pruning mechanism, GLiDeS. PTTP+GLiDeS combines modified versions of Stickel's PTTP style prover [6] and the model generator MACE [4]

Efficient E-matching for SMT solvers

Satisfiability Modulo Theories (SMT) solvers have proven highly scalable, efficient and suitable for integrating theory reasoning. However, for numerous applications from program analysis and verification, the ground fragment is insufficient, as proof obligations often include quantifiers. A well known approach for quantifier reasoning uses a matching algorithm that works against an E-graph to instantiate quantified variables. This paper introduces algorithms that identify matches on E-graphs incrementally and efficiently. In particular, we introduce an index that works on E-graphs, called E-matching code trees that combine features of substitution and code trees, used in saturation based theorem provers. E-matching code trees allow performing matching against several patterns simultaneously. The code trees are combined with an additional index, called the inverted path index, which filters E-graph terms that may potentially match patterns when the E-graph is updated. Experimental results show substantial performance improvements over existing state-of-the-art SMT solvers

Roberto Farias e a lógica do duplo-pensar no caso da censura ao filme Pra frente, Brasil

A presente pesquisa busca discutir as relações entre censura e representação cinematográfica da ditadura civil-militar brasileira nos anos finais do regime, a partir do caso do filme Pra frente, Brasil, dirigido por Roberto Farias e lançado nos cinemas do país no início de 1983. Avalia-se até que ponto o modo representativo e o discurso político adotados por Farias são condicionados pelas pressões censórias existentes no período ou expressam meramente um posicionamento político do cineasta em questão