Fσ set

Summary

Fσ set ranks in the top 2% of general entities by monthly Wikipedia readership (18 views/month).^[1]

Key Facts

• Fσ set's subclass of is recorded as subset^[2].
• Fσ set's subclass of is recorded as countable set^[3].
• Fσ set's part of is recorded as Borel hierarchy^[4].
• Fσ set's part of is recorded as list of types of sets^[5].
• Fσ set's opposite of is recorded as Gδ set^[6].
• Fσ set's Freebase ID is recorded as /m/023cg5^[7].
• Fσ set's defining formula is recorded as A = \bigcup_{r \in \mathbb{Q}} {(ry,y) \mid y \in \mathbb{R}}^[8].
• Fσ set's studied by is recorded as topology^[9].
• Fσ set's MathWorld ID is recorded as F-SigmaSet^[10].
• Fσ set's maintained by WikiProject is recorded as WikiProject Mathematics^[11].
• Fσ set's Microsoft Academic ID is recorded as 2777697161^[12].
• Fσ set's ProofWiki ID is recorded as Definition:F-Sigma_Set^[13].
• Fσ set's Great Russian Encyclopedia portal ID is recorded as fs-mnozhestvo-5f0478^[14].

Why It Matters

Fσ set ranks in the top 2% of general entities by monthly Wikipedia readership (18 views/month).^[1] It has Wikipedia articles in 8 language editions, a strong signal of global cultural recognition.^[15] It is known by 4 alternative names across languages and contexts.^[16]