let L be non empty transitive RelStr ; :: thesis: for S being non empty full directed-sups-inheriting SubRelStr of L
for R being non empty directed-sups-inheriting SubRelStr of S holds R is directed-sups-inheriting SubRelStr of L
let S be non empty full directed-sups-inheriting SubRelStr of L; :: thesis: for R being non empty directed-sups-inheriting SubRelStr of S holds R is directed-sups-inheriting SubRelStr of L
let R be non empty directed-sups-inheriting SubRelStr of S; :: thesis: R is directed-sups-inheriting SubRelStr of L
reconsider T = R as SubRelStr of L by YELLOW_6:16;
T is directed-sups-inheriting
proof
let X be
directed Subset of
T;
:: according to WAYBEL_0:def 4 :: thesis: ( X = {} or not ex_sup_of X,L or "\/" X,L in the carrier of T )
reconsider Y =
X as
directed Subset of
S by YELLOW_2:7;
assume A1:
X <> {}
;
:: thesis: ( not ex_sup_of X,L or "\/" X,L in the carrier of T )
assume
ex_sup_of X,
L
;
:: thesis: "\/" X,L in the carrier of T
then
(
sup Y = "\/" X,
L &
ex_sup_of Y,
S )
by A1, WAYBEL_0:7;
hence
"\/" X,
L in the
carrier of
T
by A1, WAYBEL_0:def 4;
:: thesis: verum
end;
hence
R is directed-sups-inheriting SubRelStr of L
; :: thesis: verum