let L be Lattice; for A being non empty set
for x being Element of A
for B being Finite_Subset of A
for f being Function of A,the carrier of L st x in B holds
f . x [= FinJoin B,f
let A be non empty set ; for x being Element of A
for B being Finite_Subset of A
for f being Function of A,the carrier of L st x in B holds
f . x [= FinJoin B,f
let x be Element of A; for B being Finite_Subset of A
for f being Function of A,the carrier of L st x in B holds
f . x [= FinJoin B,f
let B be Finite_Subset of A; for f being Function of A,the carrier of L st x in B holds
f . x [= FinJoin B,f
let f be Function of A,the carrier of L; ( x in B implies f . x [= FinJoin B,f )
assume
x in B
; f . x [= FinJoin B,f
then
(f . x) "\/" (FinJoin B,f) = FinJoin B,f
by SETWISEO:31;
hence
f . x [= FinJoin B,f
by LATTICES:def 3; verum