let S be non empty non void ManySortedSign ; for V being V16() ManySortedSet of the carrier of S
for o being OperSymbol of S
for p being ArgumentSeq of Sym o,V holds the_sort_of ((Sym o,V) -tree p) = the_result_sort_of o
let V be V16() ManySortedSet of the carrier of S; for o being OperSymbol of S
for p being ArgumentSeq of Sym o,V holds the_sort_of ((Sym o,V) -tree p) = the_result_sort_of o
let o be OperSymbol of S; for p being ArgumentSeq of Sym o,V holds the_sort_of ((Sym o,V) -tree p) = the_result_sort_of o
let p be ArgumentSeq of Sym o,V; the_sort_of ((Sym o,V) -tree p) = the_result_sort_of o
A1:
([o,the carrier of S] -tree p) . {} = [o,the carrier of S]
by TREES_4:def 4;
[o,the carrier of S] = Sym o,V
by MSAFREE:def 11;
hence
the_sort_of ((Sym o,V) -tree p) = the_result_sort_of o
by A1, Th17; verum