A1:
the carrier of (product J) = product (Carrier J)
by YELLOW_1:def 4;
thus
product J is directed
product J is transitive proof
let x,
y be
Element of
(product J);
YELLOW_6:def 3 ex z being Element of (product J) st
( x <= z & y <= z )
defpred S1[
Element of
Y,
object ]
means (
[(x . T),Y] in the
InternalRel of
(J . T) &
[(y . T),Y] in the
InternalRel of
(J . T) );
consider z being
ManySortedSet of the
carrier of
Y such that A4:
for
i being
Element of
Y holds
S1[
i,
z . i]
from PBOOLE:sch 6(A2);
dom z =
the
carrier of
Y
by PARTFUN1:def 2
.=
dom (Carrier J)
by PARTFUN1:def 2
;
then reconsider z =
z as
Element of
(product J) by A1, A5, CARD_3:9;
take
z
;
( x <= z & y <= z )
for
i being
object st
i in the
carrier of
Y holds
ex
R being
RelStr ex
xi,
yi being
Element of
R st
(
R = J . i &
xi = x . i &
yi = z . i &
xi <= yi )
hence
x <= z
by A1, YELLOW_1:def 4;
y <= z
for
i being
object st
i in the
carrier of
Y holds
ex
R being
RelStr ex
yi,
zi being
Element of
R st
(
R = J . i &
yi = y . i &
zi = z . i &
yi <= zi )
hence
y <= z
by A1, YELLOW_1:def 4;
verum
end;
let x, y, z be Element of (product J); YELLOW_0:def 2 ( not x <= y or not y <= z or x <= z )
assume that
A6:
x <= y
and
A7:
y <= z
; x <= z
A8:
ex fy, gz being Function st
( fy = y & gz = z & ( for i being object st i in the carrier of Y holds
ex R being RelStr ex xi, yi being Element of R st
( R = J . i & xi = fy . i & yi = gz . i & xi <= yi ) ) )
by A1, A7, YELLOW_1:def 4;
A9:
ex fx, gy being Function st
( fx = x & gy = y & ( for i being object st i in the carrier of Y holds
ex R being RelStr ex xi, yi being Element of R st
( R = J . i & xi = fx . i & yi = gy . i & xi <= yi ) ) )
by A1, A6, YELLOW_1:def 4;
for i being object st i in the carrier of Y holds
ex R being RelStr ex xi, yi being Element of R st
( R = J . i & xi = x . i & yi = z . i & xi <= yi )
proof
let i be
object ;
( i in the carrier of Y implies ex R being RelStr ex xi, yi being Element of R st
( R = J . i & xi = x . i & yi = z . i & xi <= yi ) )
assume A10:
i in the
carrier of
Y
;
ex R being RelStr ex xi, yi being Element of R st
( R = J . i & xi = x . i & yi = z . i & xi <= yi )
then reconsider j =
i as
Element of
Y ;
consider R1 being
RelStr ,
xi,
yi being
Element of
R1 such that A11:
R1 = J . i
and A12:
xi = x . i
and A13:
(
yi = y . i &
xi <= yi )
by A9, A10;
consider R2 being
RelStr ,
yi9,
zi being
Element of
R2 such that A14:
R2 = J . i
and A15:
yi9 = y . i
and A16:
zi = z . i
and A17:
yi9 <= zi
by A8, A10;
reconsider xi =
xi,
zi =
zi as
Element of
(J . j) by A11, A14;
take
J . j
;
ex xi, yi being Element of (J . j) st
( J . j = J . i & xi = x . i & yi = z . i & xi <= yi )
take
xi
;
ex yi being Element of (J . j) st
( J . j = J . i & xi = x . i & yi = z . i & xi <= yi )
take
zi
;
( J . j = J . i & xi = x . i & zi = z . i & xi <= zi )
thus
(
J . j = J . i &
xi = x . i &
zi = z . i )
by A12, A16;
xi <= zi
thus
xi <= zi
by A11, A13, A14, A15, A17, YELLOW_0:def 2;
verum
end;
hence
x <= z
by A1, YELLOW_1:def 4; verum