let X be set ; ( X is epsilon-transitive implies Tarski-Class X is epsilon-transitive )
consider A being Ordinal such that
A1:
Tarski-Class X,A = Tarski-Class X
by Th22;
A2:
Tarski-Class X,A c= Tarski-Class X,(succ A)
by Th18;
A3:
Tarski-Class X,A = Tarski-Class X,(succ A)
by A1, A2, XBOOLE_0:def 10;
assume A4:
X is epsilon-transitive
; Tarski-Class X is epsilon-transitive
thus
Tarski-Class X is epsilon-transitive
by A1, A3, A4, Th25; verum