observer ~ an entity that can get an consistent history
— Me@2017-07-28 08:20:23 PM
.
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2020.08.21 Friday (c) All rights reserved by ACHK
observer ~ an entity that can get an consistent history
— Me@2017-07-28 08:20:23 PM
.
.
2020.08.21 Friday (c) All rights reserved by ACHK