let n be Ordinal; :: thesis: for L being non empty non trivial well-unital doubleLoopStr
for u being set
for b being bag of n st support b = {u} holds
for x being Function of n,L holds eval b,x = (power L) . (x . u),(b . u)

let L be non empty non trivial well-unital doubleLoopStr ; :: thesis: for u being set
for b being bag of n st support b = {u} holds
for x being Function of n,L holds eval b,x = (power L) . (x . u),(b . u)

let u be set ; :: thesis: for b being bag of n st support b = {u} holds
for x being Function of n,L holds eval b,x = (power L) . (x . u),(b . u)

let b be bag of n; :: thesis: ( support b = {u} implies for x being Function of n,L holds eval b,x = (power L) . (x . u),(b . u) )
reconsider sb = support b as finite Subset of n ;
set sg = SgmX (RelIncl n),sb;
assume A1: support b = {u} ; :: thesis: for x being Function of n,L holds eval b,x = (power L) . (x . u),(b . u)
then A2: u in support b by TARSKI:def 1;
let x be Function of n,L; :: thesis: eval b,x = (power L) . (x . u),(b . u)
A3: rng x c= the carrier of L by RELAT_1:def 19;
A4: n = dom x by FUNCT_2:def 1;
then x . u in rng x by A2, FUNCT_1:def 5;
then reconsider xu = x . u as Element of L by A3;
A5: RelIncl n linearly_orders sb by Th15;
then A6: rng (SgmX (RelIncl n),sb) = {u} by A1, PRE_POLY:def 2;
then A7: u in rng (SgmX (RelIncl n),sb) by TARSKI:def 1;
then A8: 1 in dom (SgmX (RelIncl n),sb) by FINSEQ_3:33;
then A9: (SgmX (RelIncl n),sb) . 1 in rng (SgmX (RelIncl n),sb) by FUNCT_1:def 5;
then A10: (SgmX (RelIncl n),sb) . 1 = u by A6, TARSKI:def 1;
then 1 in dom (x * (SgmX (RelIncl n),sb)) by A4, A8, A2, FUNCT_1:21;
then A11: (x * (SgmX (RelIncl n),sb)) /. 1 = (x * (SgmX (RelIncl n),sb)) . 1 by PARTFUN1:def 8
.= x . ((SgmX (RelIncl n),sb) . 1) by A8, FUNCT_1:23
.= x . u by A6, A9, TARSKI:def 1 ;
dom b = n by PARTFUN1:def 4;
then 1 in dom (b * (SgmX (RelIncl n),sb)) by A8, A10, A2, FUNCT_1:21;
then A12: (b * (SgmX (RelIncl n),sb)) /. 1 = (b * (SgmX (RelIncl n),sb)) . 1 by PARTFUN1:def 8
.= b . ((SgmX (RelIncl n),sb) . 1) by A8, FUNCT_1:23
.= b . u by A6, A9, TARSKI:def 1 ;
A13: (power L) . xu,(b . u) = (power L) . [xu,(b . u)] ;
A14: for v being set st v in dom (SgmX (RelIncl n),sb) holds
v in {1}
proof
let v be set ; :: thesis: ( v in dom (SgmX (RelIncl n),sb) implies v in {1} )
assume A15: v in dom (SgmX (RelIncl n),sb) ; :: thesis: v in {1}
assume A16: not v in {1} ; :: thesis: contradiction
reconsider v = v as Element of NAT by A15;
(SgmX (RelIncl n),sb) /. v = (SgmX (RelIncl n),sb) . v by A15, PARTFUN1:def 8;
then A17: (SgmX (RelIncl n),sb) /. v in rng (SgmX (RelIncl n),sb) by A15, FUNCT_1:def 5;
A18: v <> 1 by A16, TARSKI:def 1;
A19: 1 < v
proof
consider k being Nat such that
A20: dom (SgmX (RelIncl n),sb) = Seg k by FINSEQ_1:def 2;
Seg k = { l where l is Element of NAT : ( 1 <= l & l <= k ) } by FINSEQ_1:def 1;
then ex m9 being Element of NAT st
( m9 = v & 1 <= m9 & m9 <= k ) by A15, A20;
hence 1 < v by A18, XXREAL_0:1; :: thesis: verum
end;
(SgmX (RelIncl n),sb) /. 1 = (SgmX (RelIncl n),sb) . 1 by A7, A15, FINSEQ_3:33, PARTFUN1:def 8;
then (SgmX (RelIncl n),sb) /. 1 in rng (SgmX (RelIncl n),sb) by A8, FUNCT_1:def 5;
then (SgmX (RelIncl n),sb) /. 1 = u by A6, TARSKI:def 1
.= (SgmX (RelIncl n),sb) /. v by A6, A17, TARSKI:def 1 ;
hence contradiction by A5, A8, A15, A19, PRE_POLY:def 2; :: thesis: verum
end;
consider y being FinSequence of the carrier of L such that
A21: len y = len (SgmX (RelIncl n),(support b)) and
A22: eval b,x = Product y and
A23: for i being Element of NAT st 1 <= i & i <= len y holds
y /. i = (power L) . ((x * (SgmX (RelIncl n),(support b))) /. i),((b * (SgmX (RelIncl n),(support b))) /. i) by Def2;
for v being set st v in {1} holds
v in dom (SgmX (RelIncl n),sb) by A8, TARSKI:def 1;
then dom (SgmX (RelIncl n),sb) = Seg 1 by A14, FINSEQ_1:4, TARSKI:2;
then A24: len (SgmX (RelIncl n),sb) = 1 by FINSEQ_1:def 3;
then y . 1 = y /. 1 by A21, FINSEQ_4:24
.= (power L) . ((x * (SgmX (RelIncl n),sb)) /. 1),((b * (SgmX (RelIncl n),sb)) /. 1) by A21, A23, A24 ;
then y = <*((power L) . (x . u),(b . u))*> by A21, A24, A12, A11, FINSEQ_1:57;
hence eval b,x = (power L) . (x . u),(b . u) by A22, A13, GROUP_4:12; :: thesis: verum