So, A infinity I will call this here and then I have a point I have 2 points this point let me call it as a x and this point is call it as O. So, now, if A infinity is here, then I have to somewhere B and B infinity and C infinity, then we call this points as origin as B, C. Let me similar these both I put it as a common point at origin, because I am this is a infinity to infinity when it seem to infinity and this is again infinity to infinity. So, I call this as B C and then my a pi call it as minus 1 this is by F and then I have a point over this O, it will call as 1 and then as usual I have D infinity if I choose this according to this.