Alien Tara lives on a planet named Confusious. He wants to go to the planet Ultron. He can use any spaceship for going to Ultron. But he is afraid of the infinity wall. No spaceship can go through this infinity wall. The breath of the wall is negligible. If Confusious and Ultron are on different sides of the wall Tara can never reach Ultron. So Tara wants to know whether or not he can go to Ultron. Tara only knows three coordinates of the wall and the coordinates of both planets. He is confirmed that all three coordinates of the wall are not collinear. He is not good at Math. For that reason, he wants your help. To make the problem simpler you can consider every planet as a point. No planet lies on the surface of the infinity wall.
This is a companion discussion topic for the original entry at https://toph.co/p/a-infinity-wall