let L be non empty LattStr ; ( L is distributive Lattice iff ( L is join-absorbing & L is satisfying_Sholander_1 ) )
thus
( L is distributive Lattice implies ( L is join-absorbing & L is satisfying_Sholander_1 ) )
by LatToSho; ( L is join-absorbing & L is satisfying_Sholander_1 implies L is distributive Lattice )
assume A1:
( L is join-absorbing & L is satisfying_Sholander_1 )
; L is distributive Lattice
then A2:
for v0, v2, v1 being Element of L holds v0 "/\" (v1 "\/" v2) = (v2 "/\" v0) "\/" (v1 "/\" v0)
;
then A3:
L is distributive
by Seventh, A1;
A4:
( L is meet-commutative & L is join-commutative )
by A2, A1, MeetCom, JoinCom;
A5:
( L is meet-associative & L is join-associative )
by A2, A1, MeetAssoc, JoinAssoc;
for v0, v1 being Element of L holds (v0 "/\" v1) "\/" v1 = v1
then
L is meet-absorbing
;
hence
L is distributive Lattice
by A3, A4, A5, A1; verum