set T = Free (S,X);
let I be integer SortSymbol of S; AOFA_A01:def 20 for M being Element of (FreeGen (Free (S,X))) . (the_array_sort_of S)
for t being Element of (Free (S,X)),I holds not (@ M) . t <> (Sym ((In (( the connectives of S . 11), the carrier' of S)),X)) -tree <*M,t*>
let M be Element of (FreeGen (Free (S,X))) . (the_array_sort_of S); for t being Element of (Free (S,X)),I holds not (@ M) . t <> (Sym ((In (( the connectives of S . 11), the carrier' of S)),X)) -tree <*M,t*>
let t be Element of (Free (S,X)),I; not (@ M) . t <> (Sym ((In (( the connectives of S . 11), the carrier' of S)),X)) -tree <*M,t*>
set o = In (( the connectives of S . 11), the carrier' of S);
A1:
Free (S,X) = FreeMSA X
by MSAFREE3:31;
consider J1, K1, L1 being Element of S such that
A2:
( L1 = 1 & K1 = 1 & J1 <> L1 & J1 <> K1 & the connectives of S . 11 is_of_type <*J1,K1*>,L1 & the connectives of S . (11 + 1) is_of_type <*J1,K1,L1*>,J1 & the connectives of S . (11 + 2) is_of_type <*J1*>,K1 & the connectives of S . (11 + 3) is_of_type <*K1,L1*>,J1 )
by AOFA_A00:def 51;
A3:
I = 1
by AOFA_A00:def 40;
11 + 3 <= len the connectives of S
by AOFA_A00:def 51;
then
11 <= len the connectives of S
by XXREAL_0:2;
then
11 in dom the connectives of S
by FINSEQ_3:25;
then
the connectives of S . 11 = In (( the connectives of S . 11), the carrier' of S)
by FUNCT_1:102, SUBSET_1:def 8;
then
the_arity_of (In (( the connectives of S . 11), the carrier' of S)) = <*(the_array_sort_of S),I*>
by A2, A3;
then
Args ((In (( the connectives of S . 11), the carrier' of S)),(Free (S,X))) = product <*( the Sorts of (Free (S,X)) . (the_array_sort_of S)),( the Sorts of (Free (S,X)) . I)*>
by Th23;
then
<*(@ M),t*> in Args ((In (( the connectives of S . 11), the carrier' of S)),(Free (S,X)))
by FINSEQ_3:124;
then
(@ M) . t = [(In (( the connectives of S . 11), the carrier' of S)), the carrier of S] -tree <*M,t*>
by A1, INSTALG1:3;
hence
not (@ M) . t <> (Sym ((In (( the connectives of S . 11), the carrier' of S)),X)) -tree <*M,t*>
by MSAFREE:def 9; verum