| 0(1) element: null | |
| 1(2) element: PyForStatement | |
| 2(3,10) READ ACCESS: lines | |
| 3(4) element: PyTargetExpression: line | |
| 4(5) WRITE ACCESS: line | |
| 5(6) element: PyIfStatement | |
| 6(7,3,10) READ ACCESS: line | |
| 7(8) element: PyStatementList. Condition: line == '@':true | |
| 8(9) element: PyAssignmentStatement | |
| 9(3,10) WRITE ACCESS: head | |
| 10() element: null |