let X, x, y, z be set ; :: thesis: for R being transitive total Relation of X st [x,y] in R & [y,z] in R holds
[x,z] in R
let R be transitive total Relation of X; :: thesis: ( [x,y] in R & [y,z] in R implies [x,z] in R )
A1:
field R = X
by ORDERS_1:97;
assume
( [x,y] in R & [y,z] in R )
; :: thesis: [x,z] in R
then A2:
( x in X & y in X & z in X & [x,y] in R & [y,z] in R )
by Lm1;
R is_transitive_in X
by A1, RELAT_2:def 16;
hence
[x,z] in R
by A2, RELAT_2:def 8; :: thesis: verum