> what is the procedure to copy an object and paste it in the same document?
1 - use the 'translate' tool with the 'copy option' checked.
2 - use the normal ctrl-c > ctrl-v sequence (if it doesn't have to be exact
3 - use 2 and follow with moving the 'about point' on the resulting
object and snapping it to any other object to get exact placement.
There are probably more options. A lot depends on what you want to achieve.