:: deftheorem Def7 defines { ENUMSET1:def 7 :
for x1, x2, x3, x4, x5, x6, x7, x8, x9 being object
for b₁₀ being set holds
( b₁₀ = {x1,x2,x3,x4,x5,x6,x7,x8,x9} iff for x being object holds
( x in b₁₀ iff ( x = x1 or x = x2 or x = x3 or x = x4 or x = x5 or x = x6 or x = x7 or x = x8 or x = x9 ) ) );