let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in { p where p is Point of (TOP-REAL 2) : ( P1[p] & p <> 0. (TOP-REAL 2) ) } or x in the carrier of ((TOP-REAL 2) | F1()) )
A2: F1() ` = {(0. (TOP-REAL 2))} by A1, JGRAPH_3:30;
assume x in { p where p is Point of (TOP-REAL 2) : ( P1[p] & p <> 0. (TOP-REAL 2) ) } ; :: thesis: x in the carrier of ((TOP-REAL 2) | F1())
then consider p being Point of (TOP-REAL 2) such that
A3: ( x = p & P1[p] & p <> 0. (TOP-REAL 2) ) ;
now end;
hence x in the carrier of ((TOP-REAL 2) | F1()) by PRE_TOPC:29; :: thesis: verum