let L be non empty transitive RelStr ; :: thesis: for S being non empty infs-closed Subset of L
for X being Subset of S st ex_inf_of X,L holds
( ex_inf_of X, subrelstr S & "/\" X,(subrelstr S) = "/\" X,L )
let S be non empty infs-closed Subset of L; :: thesis: for X being Subset of S st ex_inf_of X,L holds
( ex_inf_of X, subrelstr S & "/\" X,(subrelstr S) = "/\" X,L )
let X be Subset of S; :: thesis: ( ex_inf_of X,L implies ( ex_inf_of X, subrelstr S & "/\" X,(subrelstr S) = "/\" X,L ) )
A1:
subrelstr S is non empty full infs-inheriting SubRelStr of L
by Def3;
A2:
X is Subset of (subrelstr S)
by YELLOW_0:def 15;
assume A3:
ex_inf_of X,L
; :: thesis: ( ex_inf_of X, subrelstr S & "/\" X,(subrelstr S) = "/\" X,L )
then
"/\" X,L in the carrier of (subrelstr S)
by A1, A2, YELLOW_0:def 18;
hence
( ex_inf_of X, subrelstr S & "/\" X,(subrelstr S) = "/\" X,L )
by A2, A3, YELLOW_0:64; :: thesis: verum