0(1) element: null 1(2) element: PyMatchStatement 2(3,15) refutable pattern: [x] 3(4,15) WRITE ACCESS: x 4(5) matched pattern: [x] 5(6) element: PyBinaryExpression 6(7,8) READ ACCESS: x 7(15) element: null. Condition: x > 0:false 8(9) element: null. Condition: x > 0:true 9(10,11) READ ACCESS: x 10(15) element: null. Condition: x % 2 == 0:false 11(12) element: null. Condition: x % 2 == 0:true 12(13) element: PyStatementList 13(14) element: PyExpressionStatement 14(16) READ ACCESS: y 15(16) ASSERTTYPE ACCESS: null 16(17) element: PyExpressionStatement 17(18) READ ACCESS: z 18() element: null