let x be object ; RELAT_2:def 1,PCS_0:def 9 ( not x in the carrier of [^P,Q^] or [^,^] in the ToleranceRel of [^P,Q^] )
assume
x in the carrier of [^P,Q^]
; [^,^] in the ToleranceRel of [^P,Q^]
then consider x1, x2 being object such that
A1:
x1 in the carrier of P
and
A2:
x2 in the carrier of Q
and
A3:
x = [x1,x2]
by ZFMISC_1:def 2;
reconsider D2 = the carrier of Q as non empty set by A2;
reconsider TQ = the ToleranceRel of Q as Relation of D2 ;
D2 = field TQ
by ORDERS_1:12;
then
TQ is_reflexive_in D2
by RELAT_2:def 9;
then
[x2,x2] in TQ
by A2;
hence
[^,^] in the ToleranceRel of [^P,Q^]
by A1, A2, A3, Def3; verum