let S be non empty non void ManySortedSign ; for V being non-empty ManySortedSet of the carrier of S
for o being OperSymbol of S
for a being ArgumentSeq of Sym (o,V)
for i being Nat st i in dom a holds
for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
let V be non-empty ManySortedSet of the carrier of S; for o being OperSymbol of S
for a being ArgumentSeq of Sym (o,V)
for i being Nat st i in dom a holds
for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
let o be OperSymbol of S; for a being ArgumentSeq of Sym (o,V)
for i being Nat st i in dom a holds
for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
let a be ArgumentSeq of Sym (o,V); for i being Nat st i in dom a holds
for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
let i be Nat; ( i in dom a implies for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i ) )
assume
i in dom a
; for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
then
ex t being Term of S,V st
( t = a . i & t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
by Lm8;
hence
for t being Term of S,V st t = a . i holds
( t = a /. i & the_sort_of t = (the_arity_of o) . i & the_sort_of t = (the_arity_of o) /. i )
; verum