An Algebraic Preservation Theorem for Aleph-Zero Categorical Quantified Constraint Satisfaction

23 p. -- An extended abstract of this work appears in the proceedings of the 2012 ACM/IEEE Symposium on Logic in Computer Science

Beyond Q-Resolution and Prenex Form: a Proof System for Quantified Constraint Satisfaction

We consider the quanti fied constraint satisfaction problem (QCSP) which is to decide, given a structure and a first-order sentence (not assumed here to be in prenex form) built from conjunction and quanti fication, whether or not the sentence is true on the structure. We present a proof system for certifying the falsity of QCSP instances and develop its basic theory; for instance, we provide an algorithmic interpretation of its behavior. Our proof system places the established Q-resolution proof system in a broader context, and also allows us to derive QCSP tractability results.

"Verwundete Orte" in Hettches Nox und Pareis Die Schattenboxerin

[EN] Body and space play a determinant role in the formation of societies, according to the social analyst Richard Sennet. His thesis that the configuration of spaces in history, such as that of the cities, is closely linked to the perception of the own body offers a relevant theorethical approach for the analysis of Nox (1995) by Thomas Hettche and Die Schattenboxerin (1999) by Inka Parei. In both novels bodies are perceived conscientiously by the self as a wounded and exhausted “I”, but also as a rebellious and fighting “self”. Both novels offer a concept of the body as an inadequate and wounded space, which is actually a key procedure to successfully face the similarly unstable geographical, social and political context of Germany after the Fall of the Berlin Wall.