let X, x be set ; for U being non empty set
for R being total reflexive Relation of U
for f being Function of X,U st x in X holds
f is {[x,x]},R -respecting
let U be non empty set ; for R being total reflexive Relation of U
for f being Function of X,U st x in X holds
f is {[x,x]},R -respecting
let R be total reflexive Relation of U; for f being Function of X,U st x in X holds
f is {[x,x]},R -respecting
let f be Function of X,U; ( x in X implies f is {[x,x]},R -respecting )
reconsider E = {[x,x]} as Relation ;
assume A1:
x in X
; f is {[x,x]},R -respecting
then reconsider XX = X as non empty set ;
reconsider ff = f as Function of XX,U ;
now for x1, x2 being set st [x1,x2] in E holds
[(f . x1),(f . x2)] in Rlet x1,
x2 be
set ;
( [x1,x2] in E implies [(f . x1),(f . x2)] in R )assume
[x1,x2] in E
;
[(f . x1),(f . x2)] in Rthen A2:
[x1,x2] = [x,x]
by TARSKI:def 1;
then A3:
(
x1 = x &
x2 = x )
by XTUPLE_0:1;
reconsider x11 =
x1,
x22 =
x2 as
Element of
XX by A1, A2, XTUPLE_0:1;
(
ff . x11 in U &
ff . x22 in U &
ff . x11 = ff . x22 )
by A3;
hence
[(f . x1),(f . x2)] in R
by EQREL_1:5;
verum end;
hence
f is {[x,x]},R -respecting
; verum