theorem SetFor10: :: NUMBER12:1

for x1, x2, x3, x4, x5, x6, x7, x8, x9, x10 being object holds {x1,x2,x3,x4,x5,x6,x7,x8,x9,x10} = {x1,x2,x3,x4,x5} \/ {x6,x7,x8,x9,x10}