•Please carefully consider the following precautions before deleting your account.

•Immediately after deleting your account, member information and created collections will become inaccessible within the service. They will be permanently deleted after 14-day grace period for the recovery of unintentional account deletion and to prevent misuse.

•You can rejoin using the same Google account 7 days after withdrawl.

•Note that your work history prior deleting your account will not be recovered upon rejoining in any ways.

Permanence and Impermanence of Mathematical Concepts

Permanence and Impermanence of Mathematical Concepts