let X be non empty TopSpace; :: thesis: for Z being monotone-convergence T_0-TopSpace
for Y being non empty SubSpace of Z
for f being continuous Function of Z,Y st f is being_a_retraction holds
oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y

let Z be monotone-convergence T_0-TopSpace; :: thesis: for Y being non empty SubSpace of Z
for f being continuous Function of Z,Y st f is being_a_retraction holds
oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y

let Y be non empty SubSpace of Z; :: thesis: for f being continuous Function of Z,Y st f is being_a_retraction holds
oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y

set XY = oContMaps X,Y;
set XZ = oContMaps X,Z;
reconsider uXZ = oContMaps X,Z as non empty up-complete Poset by Th8;
let f be continuous Function of Z,Y; :: thesis: ( f is being_a_retraction implies oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y )
set F = oContMaps X,f;
reconsider sXY = oContMaps X,Y as non empty full SubRelStr of uXZ by Th17;
assume A1: f is being_a_retraction ; :: thesis: oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y
then reconsider Y9 = Y as monotone-convergence T_0-TopSpace by Lm1;
oContMaps X,Y9 is up-complete by Th8;
hence oContMaps X,f is directed-sups-preserving Function of (oContMaps X,Z),(oContMaps X,Y) by Th14; :: according to YELLOW16:def 1 :: thesis: ( (oContMaps X,f) | the carrier of (oContMaps X,Y) = id (oContMaps X,Y) & oContMaps X,Y is SubRelStr of oContMaps X,Z )
A2: the carrier of sXY c= the carrier of uXZ by YELLOW_0:def 13;
A3: now
let x be set ; :: thesis: ( x in the carrier of (oContMaps X,Y) implies (id (oContMaps X,Y)) . x = ((oContMaps X,f) | the carrier of (oContMaps X,Y)) . x )
A4: dom f = the carrier of Z by FUNCT_2:def 1;
A5: ( rng f = the carrier of Y & f is idempotent ) by A1, YELLOW16:46, YELLOW16:47;
assume A6: x in the carrier of (oContMaps X,Y) ; :: thesis: (id (oContMaps X,Y)) . x = ((oContMaps X,f) | the carrier of (oContMaps X,Y)) . x
then reconsider a = x as Element of (oContMaps X,Z) by A2;
reconsider a = a as continuous Function of X,Z by Th2;
x is Function of X,Y by A6, Th2;
then rng a c= the carrier of Y by RELAT_1:def 19;
then f * a = a by A5, A4, YELLOW16:4;
hence (id (oContMaps X,Y)) . x = f * a by A6, FUNCT_1:35
.= (oContMaps X,f) . a by Def2
.= ((oContMaps X,f) | the carrier of (oContMaps X,Y)) . x by A6, FUNCT_1:72 ;
:: thesis: verum
end;
(oContMaps X,f) | the carrier of (oContMaps X,Y) is Function of the carrier of (oContMaps X,Y),the carrier of (oContMaps X,Y) by A2, FUNCT_2:38;
then ( dom (id (oContMaps X,Y)) = the carrier of (oContMaps X,Y) & dom ((oContMaps X,f) | the carrier of (oContMaps X,Y)) = the carrier of (oContMaps X,Y) ) by FUNCT_2:def 1, RELAT_1:71;
hence (oContMaps X,f) | the carrier of (oContMaps X,Y) = id (oContMaps X,Y) by A3, FUNCT_1:9; :: thesis: oContMaps X,Y is SubRelStr of oContMaps X,Z
Omega Y is full directed-sups-inheriting SubRelStr of Omega Z by A1, Th18, WAYBEL25:17;
then ( oContMaps X,Y9 is non empty full directed-sups-inheriting SubRelStr of (Omega Y) |^ the carrier of X & (Omega Y) |^ the carrier of X is full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X ) by WAYBEL24:def 3, WAYBEL25:43, YELLOW16:41, YELLOW16:44;
then ( oContMaps X,Z is non empty full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X & oContMaps X,Y is full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X ) by WAYBEL24:def 3, WAYBEL25:43, YELLOW16:28, YELLOW16:29;
hence oContMaps X,Y is SubRelStr of oContMaps X,Z by Th17, YELLOW16:30; :: thesis: verum