The compiler inserts a goto to the statement following the comefrom statement into the line specified. :^)

If multiple comefroms to the same line are specified, the comefrom to jump to is selected randomly.

It is like a regular goto, but with the label and statement reversed.

So instead of

  label: 
  do_something
  goto label

You have

  comefrom label
  do_something
  label:

Really, that's just syntax. Declare your labels with "comefrom", and ":" means "jump". But it looks a lot more confusing this way.

It is reverse GOTO. After (or before - your choice) that line is executed, execution jumps to the comefrom.