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Example of 'a subroutine may have several entry and exit points'

I'm reading the paper of Non structured programming, and found it says:

Unlike a procedure, a subroutine may have several entry and exit points, and a direct jump into or out of subroutine is (theoretically) allowed

I can't understand it, could anyone give me an code sample of:

  • a subroutine may have several entry and exit points
  • a direct jump into or out of subroutine

Thanks

Solution 
  • 10 A = 1
20 GOSUB 100
30 A = 2
40 GOSUB 110
50 A = 3
60 GOTO 130
70 END

100 PRINT A
110 PRINT "HELLO"
120 IF A = 1 THEN RETURN
130 PRINT "THERE"
140 IF A = 3 THEN GOTO 70
150 RETURN

    The subroutine has three entry points (lines 100, 110, and 130) and three exit points (lines 120, 140, and 150). There is a direct jump into line 130 (from line 60) and a direct jump out (at line 140).