10. Consider the following Java-like program that uses

 static scoping.

 void fun() {

 int a, b, c; /* definition 1 */

 ...

 while (...) {

 int a, c, d; /* definition 2 */

 ... <------------------------- 1

 while (...) {

 int d, e, f; /* definition 3 */

 ... <----------------------- 2

 }

 ... <------------------------- 3

 }

 ... <--------------------------- 4

 }

 For each of the four statements labeled 1-4 in this function, list

 all visible variables along with the definition statements (1-3)

 that define them.