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Single Idea 10285

[from 'First-Order Logic' by Wilfrid Hodges, in 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 Reference

'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).