reserve x,A,B,X,X9,Y,Y9,Z,V for set;

theorem Th74:
  X meets Y /\ Z implies X meets Y
proof
  assume X meets Y /\ Z;
  then consider x being object such that
A1: x in X and
A2: x in Y /\ Z by XBOOLE_0:3;
  x in Y by A2,XBOOLE_0:def 4;
  hence thesis by A1,XBOOLE_0:3;
end;
