let S be non empty non void ManySortedSign ; for X being non-empty ManySortedSet of the carrier of S
for o being OperSymbol of S
for p being DTree-yielding FinSequence st [o, the carrier of S] -tree p in the Sorts of (FreeMSA X) . (the_result_sort_of o) holds
len p = len (the_arity_of o)
let X be non-empty ManySortedSet of the carrier of S; for o being OperSymbol of S
for p being DTree-yielding FinSequence st [o, the carrier of S] -tree p in the Sorts of (FreeMSA X) . (the_result_sort_of o) holds
len p = len (the_arity_of o)
let o be OperSymbol of S; for p being DTree-yielding FinSequence st [o, the carrier of S] -tree p in the Sorts of (FreeMSA X) . (the_result_sort_of o) holds
len p = len (the_arity_of o)
let p be DTree-yielding FinSequence; ( [o, the carrier of S] -tree p in the Sorts of (FreeMSA X) . (the_result_sort_of o) implies len p = len (the_arity_of o) )
set s = the_result_sort_of o;
assume A1:
[o, the carrier of S] -tree p in the Sorts of (FreeMSA X) . (the_result_sort_of o)
; len p = len (the_arity_of o)
FreeMSA X = MSAlgebra(# (FreeSort X),(FreeOper X) #)
by MSAFREE:def 14;
then
[o, the carrier of S] -tree p in FreeSort (X,(the_result_sort_of o))
by A1, MSAFREE:def 11;
then A2:
[o, the carrier of S] -tree p in { a where a is Element of TS (DTConMSA X) : ( ex x being set st
( x in X . (the_result_sort_of o) & a = root-tree [x,(the_result_sort_of o)] ) or ex o being OperSymbol of S st
( [o, the carrier of S] = a . {} & the_result_sort_of o = the_result_sort_of o ) ) }
by MSAFREE:def 10;
the carrier of S in { the carrier of S}
by TARSKI:def 1;
then
[o, the carrier of S] in [: the carrier' of S,{ the carrier of S}:]
by ZFMISC_1:87;
then reconsider nt = [o, the carrier of S] as NonTerminal of (DTConMSA X) by MSAFREE:6;
reconsider O = [: the carrier' of S,{ the carrier of S}:] \/ (Union (coprod X)) as non empty set ;
reconsider R = REL X as Relation of O,(O *) ;
A3:
DTConMSA X = DTConstrStr(# O,R #)
by MSAFREE:def 8;
then reconsider TSDT = TS (DTConMSA X) as Subset of (FinTrees O) ;
reconsider c = nt as Element of O by A3;
for x being object st x in TSDT holds
x is DecoratedTree of O
;
then reconsider TSDT = TSDT as DTree-set of O by TREES_3:def 6;
consider a being Element of TS (DTConMSA X) such that
A4:
a = [o, the carrier of S] -tree p
and
( ex x being set st
( x in X . (the_result_sort_of o) & a = root-tree [x,(the_result_sort_of o)] ) or ex o being OperSymbol of S st
( [o, the carrier of S] = a . {} & the_result_sort_of o = the_result_sort_of o ) )
by A2;
a . {} = [o, the carrier of S]
by A4, TREES_4:def 4;
then consider ts being FinSequence of TS (DTConMSA X) such that
A5:
a = nt -tree ts
and
A6:
nt ==> roots ts
by DTCONSTR:10;
reconsider ts9 = ts as FinSequence of TSDT ;
reconsider b = roots ts9 as FinSequence of O ;
reconsider b = b as Element of O * by FINSEQ_1:def 11;
[c,b] in R
by A6, A3, LANG1:def 1;
then A7:
len (roots ts) = len (the_arity_of o)
by MSAFREE:def 7;
reconsider ts = ts as DTree-yielding FinSequence ;
A8:
dom (roots ts) = dom ts
by TREES_3:def 18;
ts = p
by A4, A5, TREES_4:15;
hence
len p = len (the_arity_of o)
by A7, A8, FINSEQ_3:29; verum