let M be PseudoMetricSpace; :: thesis: set_in_rel M c= [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):]
for VQv being Element of [:(M -neighbour ),(M -neighbour ),REAL :] st VQv in set_in_rel M holds
VQv in [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):]
proof
let VQv be
Element of
[:(M -neighbour ),(M -neighbour ),REAL :];
:: thesis: ( VQv in set_in_rel M implies VQv in [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):] )
assume
VQv in set_in_rel M
;
:: thesis: VQv in [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):]
then consider V,
Q being
Element of
M -neighbour ,
v being
Element of
REAL such that A1:
(
VQv = [V,Q,v] &
V,
Q is_dst v )
by Th46;
A2:
V in elem_in_rel_1 M
by A1;
A3:
Q in elem_in_rel_2 M
by A1;
v in real_in_rel M
by A1;
hence
VQv in [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):]
by A1, A2, A3, MCART_1:73;
:: thesis: verum
end;
hence
set_in_rel M c= [:(elem_in_rel_1 M),(elem_in_rel_2 M),(real_in_rel M):]
by SUBSET_1:7; :: thesis: verum