Diagonal Argument

Set Theory Jottings 32. Forcing: The Basic Lemmas August 30, 2026 - (0)
Prev TOC Next Here are the key facts about forcing, as we’ve defined it. As before, φ is a closed formula in ℒ(PA+G). Extension Lemma: If p⊩*φ and q≥p, then q⊩*φ. Truth Lemma: If A is generic, then A⊩*φ iff (ℕ,A)⊧φ. Empty Condition Lemma: If φ belongs to ℒ(PA) (no G’s), then ∅⊩*φ iff ℕ⊧φ. […]
Set Theory Jottings 31. Forcing: Intuition and Basic Definitions August 26, 2026 - (0)
From Kepler to Ptolemy 27 August 23, 2026 - (0)
Set Theory Jottings 30. Definability Tools August 9, 2026 - (0)
Set Theory Jottings 29. Definability August 5, 2026 - (3)

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