0(1) element: null
1(2) element: PyMatchStatement
2(3) WRITE ACCESS: x
3(4,5) READ ACCESS: x
4(8) element: null. Condition: x > 0:false
5(6) element: null. Condition: x > 0:true
6(7) element: PyExpressionStatement
7(8) READ ACCESS: y
8(9) element: PyExpressionStatement
9(10) READ ACCESS: z
10() element: null