externcrate reachability_solver;usereachability_solver::solve;fnmain(){// This example shows that no initial nodes can reach each other.
//// It means that `(A -> B) ∧ (B -> A)` is alway false,
// either because they are forming a loop, or because they are disconnected.
//// 1 3
// | |
// 4--5--6
// | |
// 7 9
// | |
// 10-11-12
//println!("{:?}",solve(vec![[1,4],[3,6],[5,6],[6,9],[9,12],[12,11],[11,10],[10,7],[7,4],[4,5]]))}