Scott Sturgeon has recently challenged Pollock’s account of undercutting defeaters. The challenge involves three primary contentions: (1) the account is both too strong and too weak, (2) undercutting defeaters exercise their power to defeat only in conjunction with higher-order beliefs about the basis of the lower-order beliefs whose justification they target, and (3) since rebutting defeaters ...

The cavability assessment of rock mass cavability and indicating the damage profile ahead of a cave-back is of great importance in the evaluation of a caving mine operation, which can influence all aspects of the mine operation. Due to the lack of access to the caved zones, our current knowledge about the damage profile in caved zones is very limited. Among the different approaches available, p...

Rule-based argumentation systems are developed for reasoning about defeasible information. They take as input a theory made of a set of strict rules, which encode strict information, and a set of defeasible rules which describe general behaviour with exceptional cases. They build arguments by chaining such rules, define attacks between them, use a semantics for evaluating the arguments, and fin...

Dynamic change at the marine-terminating margins of the Greenland Ice Sheet may be initiated by the ocean, particularly where subglacial runoff drives vigorous ice-marginal plumes and rapid submarine melting. Here we model submarine melt-driven undercutting of tidewater glacier termini, simulating a process which is key to understanding ice-ocean coupling. Where runoff emerges from broad subgla...

It is well-documented that employers refuse to hire workers who offer their services at less than the prevailing wage. The received explanation is that workers are motivated by reciprocity they desire to reward kindness and punish hostility. To refuse an outsider’s under-bid is viewed as a kind choice that is met with good effort; a low wage is viewed as an insult that is met with shirking. We...

In this work we will combine two important notions for the argumentation community into Abstract Argumentation Frameworks (AFs). These notions correspond to Toulmin’s backings and Pollock’s undercutting defeaters. We will define Backing-Undercutting Argumentation Frameworks (BUAFs), an extension of AFs that includes a specialized support relation, a distinction between different attack types, a...

Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers...

Acknowledgement: I appreciate the constructive comments of Andrew Austin and three anonymous referees for the Journal of Economic Education. Abstract I present a brief classroom demonstration illustrating Bertrand price undercutting. The classroom demonstration is appropriate for Micro Principles, and both intermediate and upper level undergraduate, as well as graduate classes in micro, Industr...