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Additive notation uses $+$ for the group operation and $0$ for the identity element, while multiplicative notation uses $\times$ for the operation and $1$ for the identity. These are notational conventions for abstract groups and do not require the elements to be numbers.

Conditions: Used for abstract groups.; The choice of notation changes the symbols for operation and identity but not the underlying group structure.

Additive notation uses $+$ for the group operation and $0$ for the identity element, while multiplicative notation uses $\times$ for the operation and $1$ for the identity. These are notational conventions for abstract groups and do not require the elements to be numbers.

Conditions: Used for abstract groups.; The choice of notation changes the symbols for operation and identity but not the underlying group structure.

$\langle x \rangle$ is the subgroup generated by $x$, which is the smallest subgroup of $G$ containing $x$. It is built by including $x$, its inverse $x^{-1}$, the identity $1$, and all integral powers of $x$ and $x^{-1}$ required for closure.

Conditions: $G$ is a group with operation $\times$.; $x \in G$.

$\langle x \rangle$ is the subgroup generated by $x$, which is the smallest subgroup of $G$ containing $x$. It is built by including $x$, its inverse $x^{-1}$, the identity $1$, and all integral powers of $x$ and $x^{-1}$ required for closure.

Conditions: $G$ is a group with operation $\times$.; $x \in G$.

Any subgroup containing $x$ must also contain its inverse $x^{-1}$ and the identity element $1$ because these are required by the definition of a subgroup. Additionally, closure under the group operation forces the inclusion of all integral powers of $x$ and $x^{-1}$.

Conditions: $G$ is a group.; $H \le G$ is a subgroup.; $x \in H$.

Any subgroup containing $x$ must also contain its inverse $x^{-1}$ and the identity element $1$ because these are required by the definition of a subgroup. Additionally, closure under the group operation forces the inclusion of all integral powers of $x$ and $x^{-1}$.

Conditions: $G$ is a group.; $H \le G$ is a subgroup.; $x \in H$.

No, writing $+$ or $\times$ does not mean the group elements are numbers. These are abstract notational conventions.

Conditions: Used for abstract groups.; The choice of notation changes the symbols for operation and identity but not the underlying group structure.

No, writing $+$ or $\times$ does not mean the group elements are numbers. These are abstract notational conventions.

Conditions: Used for abstract groups.; The choice of notation changes the symbols for operation and identity but not the underlying group structure.

In additive notation, for a group $H$ with operation $+$ and an element $y \in H$, the subgroup generated by $y$ is the smallest subgroup of $H$ containing $y$. It consists of all integer multiples of $y$, written as $\langle y \rangle = \{\dots, -3y, -2y, -y, 0, y, 2y, 3y, \dots\}$.

Conditions: $H$ is a group with operation $+$.; $y \in H$.

In additive notation, for a group $H$ with operation $+$ and an element $y \in H$, the subgroup generated by $y$ is the smallest subgroup of $H$ containing $y$. It consists of all integer multiples of $y$, written as $\langle y \rangle = \{\dots, -3y, -2y, -y, 0, y, 2y, 3y, \dots\}$.

Conditions: $H$ is a group with operation $+$.; $y \in H$.