let D1, D2 be DecoratedTree; ( dom D1 = tree (dom T),P,(dom T1) & ( for q being FinSequence of NAT holds
( not q in tree (dom T),P,(dom T1) or for p being FinSequence of NAT st p in P holds
( not p is_a_prefix_of q & D1 . q = T . q ) or ex p, r being FinSequence of NAT st
( p in P & r in dom T1 & q = p ^ r & D1 . q = T1 . r ) ) ) & dom D2 = tree (dom T),P,(dom T1) & ( for q being FinSequence of NAT holds
( not q in tree (dom T),P,(dom T1) or for p being FinSequence of NAT st p in P holds
( not p is_a_prefix_of q & D2 . q = T . q ) or ex p, r being FinSequence of NAT st
( p in P & r in dom T1 & q = p ^ r & D2 . q = T1 . r ) ) ) implies D1 = D2 )
assume that
A13:
dom D1 = tree (dom T),P,(dom T1)
and
A14:
for q being FinSequence of NAT holds
( not q in tree (dom T),P,(dom T1) or for p being FinSequence of NAT st p in P holds
( not p is_a_prefix_of q & D1 . q = T . q ) or ex p, r being FinSequence of NAT st
( p in P & r in dom T1 & q = p ^ r & D1 . q = T1 . r ) )
and
A15:
dom D2 = tree (dom T),P,(dom T1)
and
A16:
for q being FinSequence of NAT holds
( not q in tree (dom T),P,(dom T1) or for p being FinSequence of NAT st p in P holds
( not p is_a_prefix_of q & D2 . q = T . q ) or ex p, r being FinSequence of NAT st
( p in P & r in dom T1 & q = p ^ r & D2 . q = T1 . r ) )
; D1 = D2
now let q be
FinSequence of
NAT ;
( q in dom D1 implies not D1 . q <> D2 . q )assume that A18:
q in dom D1
and A19:
D1 . q <> D2 . q
;
contradictionthus
contradiction
verum end;
hence
D1 = D2
by A13, A15, TREES_2:33; verum