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Single Idea 10285

[filed under theme 5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic ]

Full Idea

I |= φ means that the formula φ is true in the interpretation I.

Gist of Idea

I |= φ means that the formula φ is true in the interpretation I

Source

Wilfrid Hodges (First-Order Logic [2001], 1.5)

Book Ref

'Blackwell Guide to Philosophical Logic', ed/tr. Goble,Lou [Blackwell 2001], p.17


A Reaction

[There should be no space between the vertical and the two horizontals!] This contrasts with |-, which means 'is proved in'. That is a syntactic or proof-theoretic symbol, whereas |= is a semantic symbol (involving truth).


The 23 ideas with the same theme [logic when interpreted, rather than mere formal systems]:

Semantics is the concepts of connections of language to reality, such as denotation, definition and truth [Tarski]
A language containing its own semantics is inconsistent - but we can use a second language [Tarski]
Tarski built a compositional semantics for predicate logic, from dependent satisfactions [Tarski, by McGee]
Tarksi invented the first semantics for predicate logic, using this conception of truth [Tarski, by Kirkham]
In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett]
Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett]
Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett]
In real reasoning semantics gives validity, not syntax [Searle]
Interpretation by assigning objects to names, or assigning them to variables first [Bostock, by PG]
A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
There are three different standard presentations of semantics [Hodges,W]
I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
When an 'interpretation' creates a model based on truth, this doesn't include Fregean 'sense' [Hodes]
Assigning an entity to each predicate in semantics is largely a technical convenience [Fine,K]
Classical semantics has referents for names, extensions for predicates, and T or F for sentences [Fine,K]
Syntactical methods of proof need only structure, where semantic methods (truth-tables) need truth [Lowe]
The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo]
We can do semantics by looking at given propositions, or by building new ones [Zalabardo]
Valuations in PC assign truth values to formulas relative to variable assignments [Sider]
Situation semantics for logics: not possible worlds, but information in situations [Mares]
An ontologically secure semantics for predicate calculus relies on sets [McGee]
In classical semantics singular terms refer, and quantifiers range over domains [Linnebo]
It is easier to imagine truth-value gaps (for the Liar, say) than for truth-value gluts (both T and F) [Horsten]