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;
reconsider sXY = oContMaps X,Y as non empty full SubRelStr of uXZ by Th17;
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 )
assume A1: f is being_a_retraction ; :: thesis: oContMaps X,f is_a_retraction_of oContMaps X,Z, oContMaps X,Y
set F = oContMaps X,f;
reconsider Y' = Y as monotone-convergence T_0-TopSpace by A1, Lm1;
oContMaps X,Y' 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: dom (id (oContMaps X,Y)) = the carrier of (oContMaps X,Y) by RELAT_1:71;
A3: the carrier of sXY c= the carrier of uXZ by YELLOW_0:def 13;
then (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 FUNCT_2:38;
then A4: dom ((oContMaps X,f) | the carrier of (oContMaps X,Y)) = the carrier of (oContMaps X,Y) by FUNCT_2:def 1;
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 )
assume A5: 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 A3;
reconsider a = a as continuous Function of X,Z by Th2;
A6: ( rng f = the carrier of Y & x is Function of X,Y ) by A1, A5, Th2, YELLOW16:46;
then ( f is idempotent & rng a c= the carrier of Y & dom f = the carrier of Z ) by A1, FUNCT_2:def 1, RELAT_1:def 19, YELLOW16:47;
then f * a = a by A6, YELLOW16:4;
hence (id (oContMaps X,Y)) . x = f * a by A5, FUNCT_1:35
.= (oContMaps X,f) . a by Def2
.= ((oContMaps X,f) | the carrier of (oContMaps X,Y)) . x by A5, FUNCT_1:72 ;
:: thesis: verum
end;
hence (oContMaps X,f) | the carrier of (oContMaps X,Y) = id (oContMaps X,Y) by A2, A4, FUNCT_1:9; :: thesis: oContMaps X,Y is SubRelStr of oContMaps X,Z
A7: oContMaps X,Y' is non empty full directed-sups-inheriting SubRelStr of (Omega Y) |^ the carrier of X by WAYBEL24:def 3, WAYBEL25:43;
A8: oContMaps X,Z is non empty full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X by WAYBEL24:def 3, WAYBEL25:43;
Omega Y is full directed-sups-inheriting SubRelStr of Omega Z by A1, Th18, WAYBEL25:17;
then (Omega Y) |^ the carrier of X is full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X by YELLOW16:41, YELLOW16:44;
then oContMaps X,Y is full directed-sups-inheriting SubRelStr of (Omega Z) |^ the carrier of X by A7, YELLOW16:28, YELLOW16:29;
hence oContMaps X,Y is SubRelStr of oContMaps X,Z by A8, Th17, YELLOW16:30; :: thesis: verum