reconsider T1 = the InternalRel of P as Relation of the carrier of P ;
consider A being non-empty MSAlgebra of S;
reconsider Z = the carrier of P --> A as ManySortedSet of the carrier of P ;
for i being set st i in the carrier of P holds
Z . i is non-empty MSAlgebra of S
by FUNCOP_1:13;
then reconsider Z = Z as MSAlgebra-Family of the carrier of P,S by PRALG_2:def 12;
take
Z
; ex F being ManySortedFunction of the InternalRel of P st
for i, j, k being Element of P st i >= j & j >= k holds
ex f1 being ManySortedFunction of (Z . i),(Z . j) ex f2 being ManySortedFunction of (Z . j),(Z . k) st
( f1 = F . j,i & f2 = F . k,j & F . k,i = f2 ** f1 & f1 is_homomorphism Z . i,Z . j )
set G = the InternalRel of P --> (id the Sorts of A);
reconsider G = the InternalRel of P --> (id the Sorts of A) as ManySortedFunction of the InternalRel of P ;
take
G
; for i, j, k being Element of P st i >= j & j >= k holds
ex f1 being ManySortedFunction of (Z . i),(Z . j) ex f2 being ManySortedFunction of (Z . j),(Z . k) st
( f1 = G . j,i & f2 = G . k,j & G . k,i = f2 ** f1 & f1 is_homomorphism Z . i,Z . j )
let i, j, k be Element of P; ( i >= j & j >= k implies ex f1 being ManySortedFunction of (Z . i),(Z . j) ex f2 being ManySortedFunction of (Z . j),(Z . k) st
( f1 = G . j,i & f2 = G . k,j & G . k,i = f2 ** f1 & f1 is_homomorphism Z . i,Z . j ) )
A1:
Z . j = A
by FUNCOP_1:13;
Z . k = A
by FUNCOP_1:13;
then consider F2 being ManySortedFunction of (Z . j),(Z . k) such that
A2:
F2 = id the Sorts of A
by A1;
assume
( i >= j & j >= k )
; ex f1 being ManySortedFunction of (Z . i),(Z . j) ex f2 being ManySortedFunction of (Z . j),(Z . k) st
( f1 = G . j,i & f2 = G . k,j & G . k,i = f2 ** f1 & f1 is_homomorphism Z . i,Z . j )
then A3:
( [j,i] in the InternalRel of P & [k,j] in the InternalRel of P )
by ORDERS_2:def 9;
field T1 = the carrier of P
by ORDERS_1:97;
then
T1 is_transitive_in the carrier of P
by RELAT_2:def 16;
then A4:
[k,i] in T1
by A3, RELAT_2:def 8;
A5:
Z . i = A
by FUNCOP_1:13;
then consider F1 being ManySortedFunction of (Z . i),(Z . j) such that
A6:
F1 = id the Sorts of A
by A1;
take
F1
; ex f2 being ManySortedFunction of (Z . j),(Z . k) st
( F1 = G . j,i & f2 = G . k,j & G . k,i = f2 ** F1 & F1 is_homomorphism Z . i,Z . j )
take
F2
; ( F1 = G . j,i & F2 = G . k,j & G . k,i = F2 ** F1 & F1 is_homomorphism Z . i,Z . j )
F2 ** F1 = id the Sorts of A
by A6, A2, MSUALG_3:3;
hence
( F1 = G . j,i & F2 = G . k,j & G . k,i = F2 ** F1 & F1 is_homomorphism Z . i,Z . j )
by A3, A5, A1, A6, A2, A4, FUNCOP_1:13, MSUALG_3:9; verum