set R = pcs-reverse P;
A1:
the carrier of (pcs-reverse P) = the carrier of P
by Def40;
A2:
the ToleranceRel of (pcs-reverse P) = the ToleranceRel of P `
by Def40;
A3:
the ToleranceRel of P is_irreflexive_in the carrier of P
by Def10;
let x be object ; RELAT_2:def 1,PCS_0:def 9 ( not x in the carrier of (pcs-reverse P) or [^,^] in the ToleranceRel of (pcs-reverse P) )
assume A4:
x in the carrier of (pcs-reverse P)
; [^,^] in the ToleranceRel of (pcs-reverse P)
then A5:
not [x,x] in the ToleranceRel of P
by A1, A3;
[x,x] in [: the carrier of (pcs-reverse P), the carrier of (pcs-reverse P):]
by A4, ZFMISC_1:87;
hence
[^,^] in the ToleranceRel of (pcs-reverse P)
by A1, A2, A5, XBOOLE_0:def 5; verum