A given monoid usually admits many presentations by generators and relations the notion of Tietze equivalence characterizes when two describe same monoid: it is case one can transform presentation into other using families so-called transformations. The goal this article to provide an abstract geometrical understanding well-known fact, constructing a model structure on category presentations, i...

Both Lowe and Tsai have presented their own versions of the theory that both indicative subjunctive conditionals are strict conditionals. We critically discuss we find each version wanting.

Conditionals frequently convey that the antecedent is relevant to consequent. Recently many authors have argued this relevance part of conventional meaning conditionals, but approach fails account for examples where a conditional used irrelevance Both types conditionals are best explained by with no requirement, and separate process coherence establishment among successive clauses in discourse....

We present an approach to the semantics of subjunctive conditionals based on the situation semantics notion of a constraint, in which the connection between antecedent A and consequent B of a conditional ‘if A were the case, B would be’ is an informational relation between types of situations. We also argue that the information contained in a hierarchy of planning schemas as commonly used in Ar...

This paper presents the first possible world semantics for concessive conditionals (i.e., even if A, C conditionals) constructed in a compositional way. First, the meaning of if is formalized through a semantics that builds on the proposal given by Stalnaker [1968]. A major difference from Stalnaker’s approach is that irrelevant conditionals (i.e., conditionals where the antecedent and the cons...

Reasoning with conditionals is central to everyday life, yet there is long-standing disagreement about the meaning of the conditional. One example is the puzzle of so-called missing-link conditionals such as "if raccoons have no wings, they cannot breathe under water." Their oddity may be taken to show that conditionals require a connection between antecedent ("raccoons have no wings") and cons...