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Single Idea 13438

[from 'Intermediate Logic' by David Bostock, in 5. Theory of Logic / G. Quantification / 1. Quantification ]

Full Idea

A formula is said to be in 'prenex normal form' (PNF) iff all its quantifiers occur in a block at the beginning, so that no quantifier is in the scope of any truth-functor.

Gist of Idea

'Prenex normal form' is all quantifiers at the beginning, out of the scope of truth-functors

Source

David Bostock (Intermediate Logic [1997], 3.7)

Book Reference

Bostock,David: 'Intermediate Logic' [OUP 1997], p.109


A Reaction

Bostock provides six equivalences which can be applied to manouevre any formula into prenex normal form. He proves that every formula can be arranged in PNF.