let n be Nat; :: thesis: for C, D being non empty finite set
for F being PartFunc of D,REAL
for A being RearrangmentGen of C st F is total & card D = card C & n in dom A holds
(FinS ((Rland (F,A)),C)) | n = FinS ((Rland (F,A)),(A . n))

let C, D be non empty finite set ; :: thesis: for F being PartFunc of D,REAL
for A being RearrangmentGen of C st F is total & card D = card C & n in dom A holds
(FinS ((Rland (F,A)),C)) | n = FinS ((Rland (F,A)),(A . n))

let F be PartFunc of D,REAL; :: thesis: for A being RearrangmentGen of C st F is total & card D = card C & n in dom A holds
(FinS ((Rland (F,A)),C)) | n = FinS ((Rland (F,A)),(A . n))

let B be RearrangmentGen of C; :: thesis: ( F is total & card D = card C & n in dom B implies (FinS ((Rland (F,B)),C)) | n = FinS ((Rland (F,B)),(B . n)) )
assume that
A1: ( F is total & card D = card C ) and
A2: n in dom B ; :: thesis: (FinS ((Rland (F,B)),C)) | n = FinS ((Rland (F,B)),(B . n))
set p = Rland (F,B);
A3: len (FinS ((Rland (F,B)),C)) = card C by A1, Th30;
defpred S1[ Nat] means ( $1 in dom B implies (FinS ((Rland (F,B)),C)) | $1 = FinS ((Rland (F,B)),(B . $1)) );
A4: len B = card C by Th1;
A5: ( dom B = Seg (len B) & dom (FinS ((Rland (F,B)),C)) = Seg (len (FinS ((Rland (F,B)),C))) ) by FINSEQ_1:def 3;
A6: for m being Nat st S1[m] holds
S1[m + 1]
proof
set f = FinS ((Rland (F,B)),C);
let m be Nat; :: thesis: ( S1[m] implies S1[m + 1] )
assume A7: S1[m] ; :: thesis: S1[m + 1]
A8: m <= m + 1 by NAT_1:11;
assume A9: m + 1 in dom B ; :: thesis: (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1)))
then 1 <= m + 1 by FINSEQ_3:25;
then A10: m + 1 in Seg (m + 1) by FINSEQ_1:1;
A11: dom (Rland (F,B)) = C by A1, Th12;
A12: m + 1 <= len B by A9, FINSEQ_3:25;
then A13: m <= len B by NAT_1:13;
A14: m < len B by A12, NAT_1:13;
A15: m <= (len B) - 1 by A12, XREAL_1:19;
A16: len ((FinS ((Rland (F,B)),C)) | (m + 1)) = m + 1 by A4, A3, A12, FINSEQ_1:59;
now :: thesis: ( ( m = 0 & (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1))) ) or ( m <> 0 & (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1))) ) )
per cases ( m = 0 or m <> 0 ) ;
case A17: m = 0 ; :: thesis: (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1)))
consider d being Element of C such that
A18: B . 1 = {d} by Th9;
A19: d in B . 1 by A18, TARSKI:def 1;
A20: 1 <= len (FinS ((Rland (F,B)),C)) by A1, Th30;
then ( 1 in Seg 1 & 1 in dom (FinS ((Rland (F,B)),C)) ) by FINSEQ_1:1, FINSEQ_3:25;
then A21: ((FinS ((Rland (F,B)),C)) | (m + 1)) . 1 = (FinS ((Rland (F,B)),C)) . 1 by A17, RFINSEQ:6
.= (FinS (F,D)) . 1 by A1, Th17
.= (Rland (F,B)) . d by A1, A19, Th14 ;
dom (Rland (F,B)) = C by A1, Th12;
then A22: FinS ((Rland (F,B)),(B . (m + 1))) = <*((Rland (F,B)) . d)*> by A17, A18, RFUNCT_3:69;
len ((FinS ((Rland (F,B)),C)) | (m + 1)) = 1 by A17, A20, FINSEQ_1:59;
hence (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1))) by A22, A21, FINSEQ_1:40; :: thesis: verum
end;
case A23: m <> 0 ; :: thesis: (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1)))
A24: Seg m c= Seg (m + 1) by A8, FINSEQ_1:5;
A25: ((FinS ((Rland (F,B)),C)) | (m + 1)) | m = ((FinS ((Rland (F,B)),C)) | (m + 1)) | (Seg m) by FINSEQ_1:def 16
.= ((FinS ((Rland (F,B)),C)) | (Seg (m + 1))) | (Seg m) by FINSEQ_1:def 16
.= (FinS ((Rland (F,B)),C)) | ((Seg (m + 1)) /\ (Seg m)) by RELAT_1:71
.= (FinS ((Rland (F,B)),C)) | (Seg m) by A24, XBOOLE_1:28
.= (FinS ((Rland (F,B)),C)) | m by FINSEQ_1:def 16 ;
A26: 0 + 1 <= m by A23, NAT_1:13;
then consider d being Element of C such that
A27: (B . (m + 1)) \ (B . m) = {d} and
B . (m + 1) = (B . m) \/ {d} and
A28: (B . (m + 1)) \ {d} = B . m by A15, Th10;
A29: d in {d} by TARSKI:def 1;
then (Rland (F,B)) . d = (FinS (F,D)) . (m + 1) by A1, A14, A26, A27, Th14
.= (FinS ((Rland (F,B)),C)) . (m + 1) by A1, Th17
.= ((FinS ((Rland (F,B)),C)) | (m + 1)) . (m + 1) by A5, A4, A3, A9, A10, RFINSEQ:6 ;
then A30: (FinS ((Rland (F,B)),C)) | (m + 1) = ((FinS ((Rland (F,B)),C)) | m) ^ <*((Rland (F,B)) . d)*> by A16, A25, RFINSEQ:7;
d in (dom (Rland (F,B))) /\ (B . (m + 1)) by A11, A27, A29, XBOOLE_0:def 4;
then A31: d in dom ((Rland (F,B)) | (B . (m + 1))) by RELAT_1:61;
A32: (FinS ((Rland (F,B)),C)) | (m + 1) is non-increasing by RFINSEQ:20;
A33: dom ((Rland (F,B)) | (B . (m + 1))) = (dom (Rland (F,B))) /\ (B . (m + 1)) by RELAT_1:61
.= B . (m + 1) by A9, A11, Lm5, XBOOLE_1:28 ;
B . (m + 1) is finite by A9, Lm5, FINSET_1:1;
then (FinS ((Rland (F,B)),C)) | (m + 1),(Rland (F,B)) | (B . (m + 1)) are_fiberwise_equipotent by A7, A13, A26, A28, A30, A31, FINSEQ_3:25, RFUNCT_3:65;
hence (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1))) by A33, A32, RFUNCT_3:def 13; :: thesis: verum
end;
end;
end;
hence (FinS ((Rland (F,B)),C)) | (m + 1) = FinS ((Rland (F,B)),(B . (m + 1))) ; :: thesis: verum
end;
A34: S1[ 0 ] by FINSEQ_3:25;
for m being Nat holds S1[m] from NAT_1:sch 2(A34, A6);
hence (FinS ((Rland (F,B)),C)) | n = FinS ((Rland (F,B)),(B . n)) by A2; :: thesis: verum