assume
not {*,non_op} misses Constructors
; contradiction
then consider x being object such that
A1:
x in {*,non_op}
and
A2:
x in Constructors
by XBOOLE_0:3;
( x in Modes \/ Attrs or x in Funcs )
by A2, XBOOLE_0:def 3;
then
( x in Modes or x in Attrs or x in Funcs )
by XBOOLE_0:def 3;
then consider Y, Z being set such that
A3:
x in [:Y,Z:]
;
A4:
ex y, z being object st
( y in Y & z in Z & [y,z] = x )
by A3, ZFMISC_1:def 2;
reconsider x = x as set by TARSKI:1;
( x = * or x = non_op )
by A1, TARSKI:def 2;
then
( the_rank_of x = 0 or the_rank_of x = 1 )
by CLASSES1:73;
then
the_rank_of x c= 1
;
then
the_rank_of x in succ (succ {})
by ORDINAL1:6, ORDINAL1:12;
then
x in Rank (succ (succ {}))
by CLASSES1:66;
hence
contradiction
by A4, CLASSES1:29, CLASSES1:45; verum