consider s being Element of S such that
A1:
s is_>=_than the carrier of S
by YELLOW_0:def 5;
consider t being Element of T such that
A2:
t is_>=_than the carrier of T
by YELLOW_0:def 5;
take
[s,t]
; :: according to YELLOW_0:def 5 :: thesis: the carrier of [:S,T:] is_<=_than [s,t]
A3:
the carrier of [:S,T:] = [:the carrier of S,the carrier of T:]
by YELLOW_3:def 2;
( the carrier of S c= the carrier of S & the carrier of T c= the carrier of T )
;
hence
the carrier of [:S,T:] is_<=_than [s,t]
by A1, A2, A3, YELLOW_3:30; :: thesis: verum