Verbally closed subgroup

From Groupprops

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]

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

Definition

Suppose is a group and is a subgroup of . We say that is verbally closed in if the following is true: For any word in letters, the image of under the word map corresponding to equals the intersection of with the image of under the word map corresponding to .

Relation with other properties

Stronger properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
retract |FULL LIST, MORE INFO
direct factor (via retract) (via retract) |FULL LIST, MORE INFO

Weaker properties

Property Meaning Proof of implication Proof of strictness (reverse implication failure) Intermediate notions
local divisibility-closed subgroup if an element of the subgroup has a root in the whole group, there is a root in the subgroup. |FULL LIST, MORE INFO
divisibility-closed subgroup if every element of the group has a root, every element of the subgroup has a root in the subgroup. (via local divisibility-closed) (via local divisibility-closed) |FULL LIST, MORE INFO
local powering-invariant subgroup if an element of the subgroup has a unique root in the group, that root is in the subgroup. (via local divisibility-closed) (via local divisibility-closed) |FULL LIST, MORE INFO
powering-invariant subgroup (via divisibility-closed) (via divisibility-closed) |FULL LIST, MORE INFO