Generic extension Created 2026-09-24 Updated 2026-09-24
If is a generic filter over a countable transitive model , the generic extension consists of the interpretations by of all forcing names in .
Past exam of the mathematics course of the University of Cambridge 2025 iii Paper 128 2 c Solution Created 2026-09-24 Updated 2026-09-24
LetFor each natural number , conditions whose stem has length at least form a dense subset of a forcing order, so the generic filter meets all of them and .
Fix . The setis dense: from replace by . Choose . Every stronger condition must put each newly added stem value above , sofor every . Thus is a dominating real over .
Past exam of the mathematics course of the University of Cambridge 2026 iii Paper 128 2 a Solution Created 2026-09-24 Updated 2026-09-24