Cleaned up C++

[via Digitalmars-d]

On Thursday, 23 April 2015 at 14:55:42 UTC, Iain Buclaw wrote:
> There are two states each local variable can be assigned.
> 1. Used
> 2. Read
>
> int a = 1;  // a = Used
> return a;  // a = Read
> printf("%d\n", a);  // a = Read
> int b = a;  // b = Used, a = Read
> int c = void; // c = Unused
>
> If a variable is unused, it's a dead variable.  If a variable 
> is used
> but not read, it's a dead variable. Simple. :-)

Proving how indexing of an array hits the array in a nontrivial 
loop is intractable for large N (any parameter you like).

(you also don't deal with binary true/false, but three outcomes: 
satisfiable, unsatisfiable and unknown)