theorem Th63:
for
A,
B,
C being
Point of
(TOP-REAL 2) st
A,
B,
C is_a_triangle holds
ex
D being
Point of
(TOP-REAL 2) st
(
(median (A,B,C)) /\ (median (B,C,A)) = {D} &
(median (B,C,A)) /\ (median (C,A,B)) = {D} &
(median (C,A,B)) /\ (median (A,B,C)) = {D} )