This deletes a node and the rest of the stream after that node. The node (and subsequent stream) is removed from the project tree as well as the workspace.
You can select the delete mode in one of four ways:
Select the node (either in the project tree or in the workspace) and click the right-hand mouse button to display the context menu, then select the delete command.
Alternatively, select the delete mode command from the mode menu.
Alternatively, click on the delete
button 
on the controls toolbar.
Alternatively, press the F4 key.
To delete a node:
Quick delete using the context menu: If the node is the last node in the stream, WITNESS Miner simply deletes the node. If the node is not the last node in the stream, WITNESS Miner displays the message: do you wish to delete the stream from this point forward? Click on OK to confirm.
Other delete methods:
WITNESS Miner displays a symbol 
next to the cursor, indicating that you must select a node for
deletion. If the node is the last node in the stream, WITNESS Miner
simply deletes the node. If the node is not the last node in the
stream, WITNESS Miner displays the message: do
you wish to delete the stream from this point forward? Click
on OK to confirm.
When you have deleted the node (or node and subsequent stream) WITNESS Miner returns to normal mode.