Question: Question 1 : x , y are integer non negative variables

i have a condition - if x > 0 then y=0 

Question 2 : a , b , c , d , e are integer non negative variables
 if any one of above > 0 then other 4 will be zero.

How to formulate above constraint as linear equations.I know how to handle above for Boolean variables but could not do for integer variable. I tried searching in other forums and WEB but could not get the solution.

Answer: 
```
struct A { virtual void foo() {} };
struct B: A { void foo() override {} };
struct C: B {};

auto main() -> int
{
    C o;
    C* p = &o;

    p->foo();    // Calls B::foo
    p->A::foo(); // Calls A::foo
}

```
If `c` is the pointer to `C`:

```
c->A::method();

```