Pseudoverbal subgroup: Difference between revisions

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! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions
! Property !! Meaning !! Proof of implication !! Proof of strictness (reverse implication failure) !! Intermediate notions
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| [[Stronger than::fully invariant subgroup]] || || [[pseudoverbal implies fully invariant]] || [[fully invariant not implies pseudoverbal]] || {{intermediate notions short|fully invariant subgroup|pseudoverbal subgroup}}
| [[Stronger than::quotient-subisomorph-containing subgroup]] || contained in the kernel of any homomorphism to the quotient group || || || {{intermediate notions short|quotient-subisomorph-containing subgroup|pseudoverbal subgroup}}
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| [[Stronger than::fully invariant subgroup]] || || (via quotient-subisomorph-containing) || (via quotient-subisomorph-containing) || {{intermediate notions short|fully invariant subgroup|pseudoverbal subgroup}}
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| [[Stronger than::characteristic subgroup]] || || ([[fully invariant implies characteristic|via fully invariant]]) || ([[characteristic not implies fully invariant|via fully invariant]]) || {{intermediate notions short|characteristic subgroup|pseudoverbal subgroup}}
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Latest revision as of 22:00, 26 July 2013

BEWARE! This term is nonstandard and is being used locally within the wiki. [SHOW MORE]

This article defines a subgroup property: a property that can be evaluated to true/false given a group and a subgroup thereof, invariant under subgroup equivalence. View a complete list of subgroup properties[SHOW MORE]

Definition

Suppose is a subpseudovariety of the variety of groups, i.e., is a collection of groups closed under taking subgroups, quotients, and direct products. Equivalently, the group property of being in is a pseudovarietal group property.

The -pseudoverbal subgroup of a group is defined as the intersection of all normal subgroups of for which the quotient group is in . Note that the quotient group of by its -pseudoverbal subgroup need not itself be in the pseudovariety.

Relation with other properties

Stronger properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
verbal subgroup similar definition, but for a subvariety instead of a subpseudovariety |FULL LIST, MORE INFO

Weaker properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
quotient-subisomorph-containing subgroup contained in the kernel of any homomorphism to the quotient group |FULL LIST, MORE INFO
fully invariant subgroup (via quotient-subisomorph-containing) (via quotient-subisomorph-containing) |FULL LIST, MORE INFO
characteristic subgroup (via fully invariant) (via fully invariant) |FULL LIST, MORE INFO