AbstractA crucial part of the contemporary interest in logicism in the philosophy of mathematics resides in its idea that arithmetical knowledge may be based on logical knowledge. Here, an implementation of this idea is considered that holds that knowledge of arithmetical principles may be based on two things: (i) knowledge of logical principles and (ii) knowledge that the arithmetical principles are representable in the logical principles. The notions of representation considered here are related to theory-based and structure-based notions of representation from contemporary mathematical logic. It is argued that the theory-based versions of such logicism are either too liberal (the plethora problem) or are committed to intuitively incorrect closure conditions (the consistency problem). Structure-based versions must on the other hand respond to a charge of begging the question (the circularity problem) or explain how one may have a knowledge of structure in advance of a knowledge of axioms (the signature problem). This discussion is significant because it gives us a better idea of what a notion of representation must look like if it is to aid in realizing some of the traditional epistemic aims of logicism in the philosophy of mathematics.

The Denjoy integral is an integral that extends the Lebesgue integral and can
integrate any derivative. In this paper, it is shown that the graph of the
indefinite Denjoy integral $f\mapsto \int_a^x f$ is a coanalytic non-Borel
relation on the product space $M[a,b]\times C[a,b]$, where $M[a,b]$ is the
Polish space of real-valued measurable functions on $[a,b]$ and where $C[a,b]$
is the Polish space of real-valued continuous functions on $[a,b]$. Using the
same methods, it is also shown that the class of indefinite Denjoy integrals,
called $ACG_{\ast}[a,b]$, is a coanalytic but not Borel subclass of the space
$C[a,b]$, thus answering a question posed by Dougherty and Kechris. Some basic
model theory of the associated spaces of integrable functions is also studied.
Here the main result is that, when viewed as an $\mathbb{R}[X]$-module with the
indeterminate $X$ being interpreted as the indefinite integral, the space of
continuous functions on the interval $[a,b]$ is elementarily equivalent to the
Lebesgue-integrable and Denjoy-integrable functions on this interval, and each
is stable but not superstable, and that they all have a common decidable theory
when viewed as $\mathbb{Q}[X]$-modules.

AbstractFrege’s theorem says that second-order Peano arithmetic is interpretable in Hume’s Principle and full impredicative comprehension. Hume’s Principle is one example of anabstraction principle, while another paradigmatic example is Basic Law V from Frege’sGrundgesetze. In this paper we study the strength of abstraction principles in the presence of predicative restrictions on the comprehension schema, and in particular we study a predicative Fregean theory which contains all the abstraction principles whose underlying equivalence relations can be proven to be equivalence relations in a weak background second-order logic. We show that this predicative Fregean theory interprets second-order Peano arithmetic (cf. Theorem 3.2).

AbstractFrege’sGrundgesetzewas one of the 19th century forerunners to contemporary set theory which was plagued by the Russell paradox. In recent years, it has been shown that subsystems of theGrundgesetzeformed by restricting the comprehension schema are consistent. One aim of this paper is to ascertain how much set theory can be developed within these consistent fragments of theGrundgesetze, and our main theorem (Theorem 2.9) shows that there is a model of a fragment of theGrundgesetzewhich defines a model of all the axioms of Zermelo–Fraenkel set theory with the exception of the power set axiom. The proof of this result appeals to Gödel’s constructible universe of sets and to Kripke and Platek’s idea of the projectum, as well as to a weak version of uniformization (which does not involve knowledge of Jensen’s fine structure theory). The axioms of theGrundgesetzeare examples ofabstraction principles, and the other primary aim of this paper is to articulate a sufficient condition for the consistency of abstraction principles with limited amounts of comprehension (Theorem 3.5). As an application, we resolve an analogue of the joint consistency problem in the predicative setting.

This paper sets out a predicative response to the Russell-Myhill paradox of
propositions within the framework of Church's intensional logic. A predicative
response places restrictions on the full comprehension schema, which asserts
that every formula determines a higher-order entity. In addition to motivating
the restriction on the comprehension schema from intuitions about the stability
of reference, this paper contains a consistency proof for the predicative
response to the Russell-Myhill paradox. The models used to establish this
consistency also model other axioms of Church's intensional logic that have
been criticized by Parsons and Klement: this, it turns out, is due to resources
which also permit an interpretation of a fragment of Gallin's intensional
logic. Finally, the relation between the predicative response to the
Russell-Myhill paradox of propositions and the Russell paradox of sets is
discussed, and it is shown that the predicative conception of set induced by
this predicative intensional logic allows one to respond to the Wehmeier
problem of many non-extensions.

This paper presents new constructions of models of Hume's Principle and Basic
Law V with restricted amounts of comprehension. The techniques used in these
constructions are drawn from hyperarithmetic theory and the model theory of
fields, and formalizing these techniques within various subsystems of
second-order Peano arithmetic allows one to put upper and lower bounds on the
interpretability strength of these theories and hence to compare these theories
to the canonical subsystems of second-order arithmetic. The main results of
this paper are: (i) there is a consistent extension of the hyperarithmetic
fragment of Basic Law V which interprets the hyperarithmetic fragment of
second-order Peano arithmetic, and (ii) the hyperarithmetic fragment of Hume's
Principle does not interpret the hyperarithmetic fragment of second-order Peano
arithmetic, so that in this specific sense there is no predicative version of
Frege's Theorem.

This article surveys recent literature by Parsons, McGee, Shapiro and others
on the significance of categoricity arguments in the philosophy of mathematics.
After discussing whether categoricity arguments are sufficient to secure
reference to mathematical structures up to isomorphism, we assess what exactly
is achieved by recent `internal' renditions of the famous categoricity
arguments for arithmetic and set theory.

AbstractThis paper presents a systematic study of the prehistory of the traditional subsystems of second-order arithmetic that feature prominently in the reverse mathematics program promoted by Friedman and Simpson. We look in particular at: (i) the long arc from Poincaré to Feferman as concerns arithmetic definability and provability, (ii) the interplay between finitism and the formalization of analysis in the lecture notes and publications of Hilbert and Bernays, (iii) the uncertainty as to the constructive status of principles equivalent to Weak König’s Lemma, and (iv) the large-scale intellectual backdrop to arithmetical transfinite recursion in descriptive set theory and its effectivization by Borel, Lusin, Addison, and others.

Before the release of the Seismic Design Criteria for California Marine Oil Terminals (Ferrito et. al, 1999), the seismic design of piers and wharves was a nonuniform procedure. Design practices of the past typically underestimated earthquake intensities, a fact that has become clear after seismic events such as the Loma Prieta (1989) and Northridge (1994) earthquakes. Based on the damage to port facilities observed in such events, the Marine Facilities Division (MFD) of the California State Lands Commission, with funding through FEMA and the California Office of Emergency Services, is developing specific regulations for the seismic performance of marine oil terminals in California. The goals of the criteria established by Ferrito et al., (1999) are to (i) ensure safe and pollution-free transfer of petroleum products between ship and land-based facilities, (ii) ensure the best achievable protection of public health, safety, and the environment, and (iii) maximize utilization of limited resources. A major component in the effort to realize these goals is the development and implementation of standardized design criteria, hence, the Seismic Design Criteria for California Marine Oil Terminals.