Questions tagged [semantics]

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4 votes
1 answer
104 views

"Operations" in category theory that are not defined for arrows

Functors in category theory are defined for both objects and arrows. Depending on how they treat arrows, functors are characterized as either covariant or contravariant. Some "operations" ...
3 votes
1 answer
180 views

Semantics of logic/relational programming languages

I'm working on some vague ideas about a logic/relational programming language based on the linear lambda calculus and having trouble coming up with some appropriate semantics. If anything the language ...
0 votes
1 answer
55 views

Are there logical devices similar to "existential variables" or "blank nodes" of Semantic Web?

In Semantic Web, alongside permanent names of things also "temporary names" named "existential variables" or "blank nodes" denoted as "_:label" are used. All ...
7 votes
0 answers
127 views

Are the non-lazy / non-weak semantics of the $\lambda$-calculus related to weak evaluation?

Vague question The most common semantics of the call-by-name $\lambda$-calculus (Hyland/Wadsworth’s observational equivalence $\approx_\text{HNF}$ and Morris’s observational equivalence $\approx_\text{...
7 votes
1 answer
97 views

Semantic read-back of sharing graphs

A "sharing graph" is a representation of a $\lambda$-term that modifies an abstract syntax tree by adding edges connecting each variable use to the place where that variable is bound. They are used ...
7 votes
0 answers
124 views

Halting problem for finitary PCF

Is the halting problem decidable for finitary PCF? By "halting problem" I mean the problem of deciding whether a closed PCF term evaluates to bottom under the denotational semantics of PCF. ...
8 votes
2 answers
361 views

What's the categorical semantics of definitional equality?

The categorical semantics of a dependent type theory is normally described as a CwA/CwF/CompCat/etc. and in these models, we can talk about propositional equality by interpreting an 'identity type'. ...
3 votes
0 answers
136 views

syntax and semantics for transfinite algorithms

Let's say I wanted to informally describe a very simple algorithm for searching through an (undirected) finite connected graph $G = (V,E)$. I could define, for each natural number $n$, a set $S_n$ and ...
4 votes
2 answers
274 views

Density of semantics in syntax

Let $L$ be a programming language, and $\cong$ a notion of equality of $L$-programs (in general $\cong$ will be undecidable). Let $syntax(n)$ be the number of $L$-programs of size $n$ (for some ...
1 vote
1 answer
162 views

What relations and differences are between formal semantics for linguistics and for programming languages?

I browsed the table of content of Cann's Formal Semantics, which reminds me of the things that I saw in programming language books. Cann's book is for linguistics, and am I right that it is helpful ...
-1 votes
1 answer
82 views

Al-Mubaid's Similarity Measure for Ontological Concepts

Al-Mubaid et al. proposed a semantic similarity measure in their research paper [1]. They see ontologies as connected graphs but refer to clusters within ontology graphs without ever defining what ...
4 votes
0 answers
103 views

Origin of simulation relations for compiler correctness

Leroy uses simulation relations as a means of showing compiler correctness; the basic idea is that a simulation relation is an asymmetric binary relation between states in two different small step ...
-2 votes
1 answer
72 views

Is there an official/academic name for the "current value" in a loop? [closed]

This is a question about semantics/vocabulary. I don't like saying "the current value you are looping over/on". I'm wondering if there is a better term.
6 votes
4 answers
7k views

Difference between syntax and semantic error in programming languages

When compilers generate errors for a specific programming language, there's distinction between syntax & semantic errors. E.g. ) + f 3 has ill-formed syntax, ...
8 votes
3 answers
393 views

Can Non-termination be considered an algebraic effect?

Non-termination is sometimes considered an effect. I have been reading about algebraic effect systems (What is algebraic about algebraic effects and handlers?), and I suspect non-termination (like ...
5 votes
1 answer
158 views

Is there a notion of "inevitable reduction?"

I was just working on a semantics paper and realized I needed a notion of inevitable reduction. I came up with this definition: Let $\rightarrow$ be a binary relation. We say that $a$ inevitably ...
6 votes
2 answers
120 views

Formal semantics of tactics

Tactics are supposed to represent inference rules in a system, and it might seem unnecessary at first to formalize the semantics of tactics; nevertheless, modern theorem provers can have pretty ...
4 votes
2 answers
626 views

What does the category of RDF models look like in Institution Theory?

The Question in short Here is the question in its pure form. Details of my reasoning can be found below. The RDF1.1 spec semantics defines a model to consist of a set IR of objects and IP of ...
5 votes
1 answer
178 views

What is a 'free model'?

I was reading this paper on effect handlers and got hung up on the phrase 'free model'. In context: [...] From an algebraic point of view, the $x_e$ provide a model for the theory of ...
8 votes
2 answers
379 views

Categorical semantics for non-monotonic logics?

Are there any categorical semantics for non-monotonic logics? It appears that the simple answer to this is "No" since the obvious notion of composition fails for any model of a non-monotonic logic. ...
21 votes
2 answers
2k views

Has the semantics of TeX (as a programming language) ever been formalized?

It seems to me that the macro language employed by $\TeX$ can maybe be seen as some kind of term rewriting system or some kind of programming language with call-by-name scoping. Even modern ...
36 votes
7 answers
8k views

Books on programming language semantics

I've been reading Nielson & Nielson's "Semantics with Applications", and I really like the subject. I'd like to have one more book on programming language semantics -- but I really can get only ...
5 votes
0 answers
95 views

Which computational models support bigotous programs?

A bigotous program is a program which decides if its input is semantically equivalent to itself. Of course, this is impossible in a Turing complete language due to Rice's theorem. In fact, its pretty ...
3 votes
2 answers
173 views

Why is the multi-step reduction of semantics reflexive?

I was reading Programming Languages and Lambda Calculi, which defines the multi-step reduction to be the reflexive-transitive closure of the one-step reduction. (Page 15, $\twoheadrightarrow_r$ is the ...
2 votes
0 answers
120 views

Applications of the monoidal closed structure in LTL?

A simple model of temporal logic is via time-indexed truth functions. This lets us model the Boolean connectives, as well as the next-step operator and modal always operator: $$ \begin{array}{lclll} ...
2 votes
0 answers
133 views

Is there is an intuitive explanation why call-by-name PCF is less expressive than both call-by-value PCF and lazy PCF?

J.C. Mitchell cites in his "Expressive power of programming languages" the result in Riecke's "Fully abstract translations between functional languages" about the call-by-value, call-by-name and lazy ...
6 votes
1 answer
341 views

Standard reference for basic model theory definitions

I am trying to give a formal presentation of the model-theoretical semantics of a language and I am a bit lost in the terminology. In particular, could somebody clarify the exact definitions of model-...
1 vote
1 answer
131 views

Observational Equivalence of open terms in PCF

The notion of observational equivalence is rather intuitive, but formally I'm having some doubts in the particular case of open terms. Lets consider the simple case where the terms ...
8 votes
2 answers
433 views

Precise definition of syntatic categories / syntatic domains in abstract syntax

I have read the introductory parts of a couple of books on programming language semantics (Gordon, Winskel, Nielson & Nielson, Allison, Stump, Schmidt), and while I do understand what they mean by ...
3 votes
1 answer
176 views

In what fields does a knowledge of formal semantics prove useful?

(If this is better for programmers SE, let me know, but I imagined you guys would have more thorough answers) I'm a mathematics major, but I have a pretty deep interest in CS (especially in compiler ...
1 vote
1 answer
131 views

How to specify and verify Horn clauses (logic programming programs)? Semantics of Horn clauses

There are lot of applications of Horn clauses (notable examples include use of rules in cognitive architectures and knowledge bases, as well as use of rules in business rules programs). Are there ...
16 votes
3 answers
739 views

Is there any programming language theory describing foreign function interfaces (FFI) and multiple language bindings?

Is there any programming language theory describing foreign function interfaces (FFI) and multiple language bindings? I have asked some implementation issues on stackoverflow, which is not suitable ...
0 votes
0 answers
241 views

How do we contribute to the lexicon of computer science?

What's the best way to contribute to the lexicon of computer science? There is an obvious organic nature to the naming of things in most sciences. The name of the discoverer is inherited or bestowed, ...
10 votes
2 answers
625 views

What's the difference between reduction strategies and evaluation strategies?

From the evaluation strategy article on Wikipedia: The notion of reduction strategy in lambda calculus is similar but distinct. From the reduction strategy article on Wikipedia: It is similar ...
1 vote
1 answer
1k views

What is the relation/difference between axiomatic and denotational semantics one one side, and the data flow analysis(DFA) on the other sied?

I am supposed to write a small paper about DFA in OOP for a CS class in theory. But I am required to connect that (DFA) to axiomatic and denotational semantics! I read few resources about axiomatic/...
1 vote
1 answer
174 views

Name a set of program variables

I am interested in the set of the variables that satisfy the following properties. I would like to find a proper name for them. We assume that a program $\phi$ has a set of variables $v_0, \ldots, ...
3 votes
2 answers
243 views

What requirements should a denotational semantics for a programming language satisfy to be correct?

We have a programming language and its denotational semantic, like Tony Hoare's CSP with its syntax and denotational semantic e.g. stable failure and UTP. We want to extend the language (its ...
9 votes
2 answers
1k views

Formal Definition/counter part in mathematics for “Objects” of Object Oriented Models

This is a question I asked in mathematics SE forum, and I was referred here. So here is the question- I'm a newbie in both formal mathematics and theoretical computer science, so please bear with me ...
6 votes
1 answer
2k views

How can I prove formally semantic equivalence of programming languages?

I would like to compare two languages which are from different programming paradigms. Both langauges are object oriented languages, but one of them a multiparadigm language because it supports ...
17 votes
2 answers
2k views

Full Completeness vs Full Abstraction of a program translation

Compiler verification efforts often come down to proving the compiler fully abstract: that it preserves and reflects (contextual) equivalences. Instead of providing full abstraction proofs, some ...
10 votes
1 answer
216 views

Program Minimization

Circuit Minimization is the problem to minimize the size of a given circuit. Is there anything similar for general programs? In particular my question is - Do there exist algorithms to minimize the ...
2 votes
2 answers
273 views

Tool for specifying operational semantics for given formally specified programming language

I am trying to translate code from one programming language into another (to be specific - from RuleML to Drools, but other pairs can be expected as well) and it would be nice to know - whether there ...
11 votes
1 answer
576 views

What exactly does "semantically observable" side-effect mean?

I have question regarding pure functions. According to the Wikipedia page one of the requisites for a pure function is : Evaluation of the result does not cause any semantically observable side ...
3 votes
2 answers
271 views

Difference between abstract machines and calculi

So, first of all: I'm not sure how to tag this question. Feel free to tag it differently. I recently started reading up on CHAMs, which can express different process calculi. Slightly confused, I go ...
2 votes
3 answers
2k views

How to define the formal and informal semantics of an algorithm as accurately as possible?

I am currently researching ways to define the semantics of programs for some ideas I have for a new programming language. Most ways to define semantics involve mapping the programming language syntax ...
16 votes
3 answers
1k views

When can we say that two programs are different?

Q1. When can we say that two programs (written in some programming language like C++) are different? The first extreme is to say that two programs are equivalent iff they are identical. The other ...
5 votes
0 answers
235 views

What's the connection between these two categories of games and innocent strategies?

Lately I've been reading a lot about game semantics and in particular the problem of PCF's full abstraction. I'm trying to understand how the definition from this article relates to the one found in ...
0 votes
1 answer
134 views

How would you define a set of 'fundamental operations' over an object? [closed]

I'm writing an implementation for a common array structure. As you would find already familiar, an array is an ordered data structure that you can transform with different (hopefully self-explained) ...
1 vote
1 answer
120 views

Is there good open source project that apply semantic web, modal logics, and similar technologies

Recently such themes as semantic web, modal logics, business rules have seen increased interest as research topics in computer science (alhough many of then have more than 80 years of history), but ...
5 votes
0 answers
258 views

Is there a Galois correspondence between a Haskell class hierarchy and its instance hierarchy?

Can we consider a Haskell class as a loose signature-only-specification (denoting a theory) and an instance as an implementation (denoting a model)? In the example below the specification of the class ...