let X be non empty set ; :: thesis: for F, G being Functional_Sequence of X,ExtREAL
for n being Nat
for x being Element of X st F is additive & F is with_the_same_dom & G is additive & G is with_the_same_dom & x in (dom (F . 0 )) /\ (dom (G . 0 )) & ( for k being Nat
for y being Element of X st y in (dom (F . 0 )) /\ (dom (G . 0 )) holds
(F . k) . y <= (G . k) . y ) holds
((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x

let F, G be Functional_Sequence of X,ExtREAL ; :: thesis: for n being Nat
for x being Element of X st F is additive & F is with_the_same_dom & G is additive & G is with_the_same_dom & x in (dom (F . 0 )) /\ (dom (G . 0 )) & ( for k being Nat
for y being Element of X st y in (dom (F . 0 )) /\ (dom (G . 0 )) holds
(F . k) . y <= (G . k) . y ) holds
((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x

let n be Nat; :: thesis: for x being Element of X st F is additive & F is with_the_same_dom & G is additive & G is with_the_same_dom & x in (dom (F . 0 )) /\ (dom (G . 0 )) & ( for k being Nat
for y being Element of X st y in (dom (F . 0 )) /\ (dom (G . 0 )) holds
(F . k) . y <= (G . k) . y ) holds
((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x

let x be Element of X; :: thesis: ( F is additive & F is with_the_same_dom & G is additive & G is with_the_same_dom & x in (dom (F . 0 )) /\ (dom (G . 0 )) & ( for k being Nat
for y being Element of X st y in (dom (F . 0 )) /\ (dom (G . 0 )) holds
(F . k) . y <= (G . k) . y ) implies ((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x )

assume that
A1: F is additive and
A2: F is with_the_same_dom and
A3: G is additive and
A4: G is with_the_same_dom and
A6: x in (dom (F . 0 )) /\ (dom (G . 0 )) and
A5: for k being Nat
for y being Element of X st y in (dom (F . 0 )) /\ (dom (G . 0 )) holds
(F . k) . y <= (G . k) . y ; :: thesis: ((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x
set PF = Partial_Sums F;
set PG = Partial_Sums G;
defpred S1[ Nat] means ((Partial_Sums F) . $1) . x <= ((Partial_Sums G) . $1) . x;
( (Partial_Sums F) . 0 = F . 0 & (Partial_Sums G) . 0 = G . 0 ) by Def0;
then B1: S1[ 0 ] by A5, A6;
B2: for k being Nat st S1[k] holds
S1[k + 1]
proof
let k be Nat; :: thesis: ( S1[k] implies S1[k + 1] )
assume B20: S1[k] ; :: thesis: S1[k + 1]
R1: (F . (k + 1)) . x <= (G . (k + 1)) . x by A5, A6;
B22: ( (Partial_Sums F) . (k + 1) = ((Partial_Sums F) . k) + (F . (k + 1)) & (Partial_Sums G) . (k + 1) = ((Partial_Sums G) . k) + (G . (k + 1)) ) by Def0;
( dom ((Partial_Sums F) . (k + 1)) = dom (F . 0 ) & dom ((Partial_Sums G) . (k + 1)) = dom (G . 0 ) ) by A1, A2, A3, A4, ADD0;
then ( x in dom ((Partial_Sums F) . (k + 1)) & x in dom ((Partial_Sums G) . (k + 1)) ) by A6, XBOOLE_0:def 4;
then B25: ( ((Partial_Sums F) . (k + 1)) . x = (((Partial_Sums F) . k) . x) + ((F . (k + 1)) . x) & ((Partial_Sums G) . (k + 1)) . x = (((Partial_Sums G) . k) . x) + ((G . (k + 1)) . x) ) by B22, MESFUNC1:def 3;
thus S1[k + 1] by B25, R1, B20, XXREAL_3:38; :: thesis: verum
end;
for k being Nat holds S1[k] from NAT_1:sch 2(B1, B2);
hence ((Partial_Sums F) . n) . x <= ((Partial_Sums G) . n) . x ; :: thesis: verum