i1 : P = poset {{a,b}, {a,c}, {b,d}, {c,d}, {e,d}};
i2 : meetExists(P, b, c) o2 = true
i3 : meetExists(P, b, e) o3 = false
i4 : Q = poset {{a,b}, {a,c}, {d,b}, {d,c}, {b,e}, {c,e}};
i5 : meetExists(Q, b, c) o5 = false