let f, g be Function of I[01] ,(TOP-REAL 2); :: thesis: for a, b, c, d being real number
for O, I being Point of I[01] st O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & (f . O) `1 = a & (f . I) `1 = b & c <= (f . O) `2 & (f . O) `2 <= d & c <= (f . I) `2 & (f . I) `2 <= d & (g . O) `2 = c & (g . I) `2 = d & a <= (g . O) `1 & (g . O) `1 <= b & a <= (g . I) `1 & (g . I) `1 <= b & a < b & c < d & ( for r being Point of I[01] holds
( not a < (f . r) `1 or not (f . r) `1 < b or not c < (f . r) `2 or not (f . r) `2 < d ) ) & ( for r being Point of I[01] holds
( not a < (g . r) `1 or not (g . r) `1 < b or not c < (g . r) `2 or not (g . r) `2 < d ) ) holds
rng f meets rng g
let a, b, c, d be real number ; :: thesis: for O, I being Point of I[01] st O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & (f . O) `1 = a & (f . I) `1 = b & c <= (f . O) `2 & (f . O) `2 <= d & c <= (f . I) `2 & (f . I) `2 <= d & (g . O) `2 = c & (g . I) `2 = d & a <= (g . O) `1 & (g . O) `1 <= b & a <= (g . I) `1 & (g . I) `1 <= b & a < b & c < d & ( for r being Point of I[01] holds
( not a < (f . r) `1 or not (f . r) `1 < b or not c < (f . r) `2 or not (f . r) `2 < d ) ) & ( for r being Point of I[01] holds
( not a < (g . r) `1 or not (g . r) `1 < b or not c < (g . r) `2 or not (g . r) `2 < d ) ) holds
rng f meets rng g
let O, I be Point of I[01] ; :: thesis: ( O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & (f . O) `1 = a & (f . I) `1 = b & c <= (f . O) `2 & (f . O) `2 <= d & c <= (f . I) `2 & (f . I) `2 <= d & (g . O) `2 = c & (g . I) `2 = d & a <= (g . O) `1 & (g . O) `1 <= b & a <= (g . I) `1 & (g . I) `1 <= b & a < b & c < d & ( for r being Point of I[01] holds
( not a < (f . r) `1 or not (f . r) `1 < b or not c < (f . r) `2 or not (f . r) `2 < d ) ) & ( for r being Point of I[01] holds
( not a < (g . r) `1 or not (g . r) `1 < b or not c < (g . r) `2 or not (g . r) `2 < d ) ) implies rng f meets rng g )
assume A1:
( O = 0 & I = 1 & f is continuous & f is one-to-one & g is continuous & g is one-to-one & (f . O) `1 = a & (f . I) `1 = b & c <= (f . O) `2 & (f . O) `2 <= d & c <= (f . I) `2 & (f . I) `2 <= d & (g . O) `2 = c & (g . I) `2 = d & a <= (g . O) `1 & (g . O) `1 <= b & a <= (g . I) `1 & (g . I) `1 <= b & a < b & c < d & ( for r being Point of I[01] holds
( not a < (f . r) `1 or not (f . r) `1 < b or not c < (f . r) `2 or not (f . r) `2 < d ) ) & ( for r being Point of I[01] holds
( not a < (g . r) `1 or not (g . r) `1 < b or not c < (g . r) `2 or not (g . r) `2 < d ) ) )
; :: thesis: rng f meets rng g
then A2:
b - a > 0
by XREAL_1:52;
A3:
d - c > 0
by A1, XREAL_1:52;
set A = 2 / (b - a);
set B = 1 - ((2 * b) / (b - a));
set C = 2 / (d - c);
set D = 1 - ((2 * d) / (d - c));
A4:
2 / (b - a) > 0
by A2, XREAL_1:141;
A5:
2 / (d - c) > 0
by A3, XREAL_1:141;
set ff = AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)));
A6:
dom (AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) = the carrier of (TOP-REAL 2)
by FUNCT_2:def 1;
A7:
dom f = the carrier of I[01]
by FUNCT_2:def 1;
A8:
dom g = the carrier of I[01]
by FUNCT_2:def 1;
A9:
AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c))) is one-to-one
by A4, A5, Th54;
reconsider f2 = (AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) * f, g2 = (AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) * g as Function of I[01] ,(TOP-REAL 2) ;
A12:
f2 is one-to-one
by A1, A9, FUNCT_1:46;
A13:
g2 is one-to-one
by A1, A9, FUNCT_1:46;
defpred S1[ Point of (TOP-REAL 2)] means ( - 1 < $1 `1 & $1 `1 < 1 & - 1 < $1 `2 & $1 `2 < 1 );
reconsider K0 = { p where p is Point of (TOP-REAL 2) : S1[p] } as Subset of (TOP-REAL 2) from JGRAPH_2:sch 1();
A14: f2 . O =
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (f . O)
by A7, FUNCT_1:23
.=
|[(((2 / (b - a)) * a) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * ((f . O) `2 )) + (1 - ((2 * d) / (d - c))))]|
by A1, Def2
;
A15: f2 . I =
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (f . I)
by A7, FUNCT_1:23
.=
|[(((2 / (b - a)) * b) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * ((f . I) `2 )) + (1 - ((2 * d) / (d - c))))]|
by A1, Def2
;
A16: g2 . O =
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (g . O)
by A8, FUNCT_1:23
.=
|[(((2 / (b - a)) * ((g . O) `1 )) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * c) + (1 - ((2 * d) / (d - c))))]|
by A1, Def2
;
A17: g2 . I =
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (g . I)
by A8, FUNCT_1:23
.=
|[(((2 / (b - a)) * ((g . I) `1 )) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * d) + (1 - ((2 * d) / (d - c))))]|
by A1, Def2
;
A18:
(f2 . O) `1 = - 1
A19: (f2 . I) `1 =
((2 / (b - a)) * b) + (1 - ((2 * b) / (b - a)))
by A15, EUCLID:56
.=
((b * 2) / (b - a)) + (1 - ((2 * b) / (b - a)))
.=
1
;
A20: (g2 . O) `2 =
((2 / (d - c)) * c) + (1 - ((2 * d) / (d - c)))
by A16, EUCLID:56
.=
((c * 2) / (d - c)) + (1 - ((2 * d) / (d - c)))
.=
((c * 2) / (d - c)) + (((d - c) / (d - c)) - ((2 * d) / (d - c)))
by A3, XCMPLX_1:60
.=
((c * 2) / (d - c)) + (((d - c) - (2 * d)) / (d - c))
.=
((c * 2) + ((d - c) - (2 * d))) / (d - c)
.=
(- (d - c)) / (d - c)
.=
- ((d - c) / (d - c))
.=
- 1
by A3, XCMPLX_1:60
;
A21: (g2 . I) `2 =
((2 / (d - c)) * d) + (1 - ((2 * d) / (d - c)))
by A17, EUCLID:56
.=
((d * 2) / (d - c)) + (1 - ((2 * d) / (d - c)))
.=
1
;
A22:
( - 1 <= (f2 . O) `2 & (f2 . O) `2 <= 1 & - 1 <= (f2 . I) `2 & (f2 . I) `2 <= 1 )
proof
reconsider s0 =
(f . O) `2 as
Real ;
A23:
(f2 . O) `2 = (((s0 - d) + (s0 - d)) - (c - d)) / (d - c)
c - d <= s0 - d
by A1, XREAL_1:11;
then
(c - d) + (c - d) <= (s0 - d) + (s0 - d)
by XREAL_1:9;
then A24:
((c - d) + (c - d)) - (c - d) <= ((s0 - d) + (s0 - d)) - (c - d)
by XREAL_1:11;
A25:
(c - d) / (d - c) =
(- (d - c)) / (d - c)
.=
- ((d - c) / (d - c))
.=
- 1
by A3, XCMPLX_1:60
;
d - d >= s0 - d
by A1, XREAL_1:11;
then
(0 + (d - d)) - (c - d) >= ((s0 - d) + (s0 - d)) - (c - d)
by XREAL_1:11;
then A26:
(d - c) / (d - c) >= (((s0 - d) + (s0 - d)) - (c - d)) / (d - c)
by A3, XREAL_1:74;
reconsider s1 =
(f . I) `2 as
Real ;
A27:
(f2 . I) `2 = (((s1 - d) + (s1 - d)) - (c - d)) / (d - c)
c - d <= s1 - d
by A1, XREAL_1:11;
then
(c - d) + (c - d) <= (s1 - d) + (s1 - d)
by XREAL_1:9;
then A28:
((c - d) + (c - d)) - (c - d) <= ((s1 - d) + (s1 - d)) - (c - d)
by XREAL_1:11;
d - d >= s1 - d
by A1, XREAL_1:11;
then
(0 + (d - d)) - (c - d) >= ((s1 - d) + (s1 - d)) - (c - d)
by XREAL_1:11;
then
(d - c) / (d - c) >= (((s1 - d) + (s1 - d)) - (c - d)) / (d - c)
by A3, XREAL_1:74;
hence
(
- 1
<= (f2 . O) `2 &
(f2 . O) `2 <= 1 &
- 1
<= (f2 . I) `2 &
(f2 . I) `2 <= 1 )
by A3, A23, A24, A25, A26, A27, A28, XREAL_1:74;
:: thesis: verum
end;
A29:
( - 1 <= (g2 . O) `1 & (g2 . O) `1 <= 1 & - 1 <= (g2 . I) `1 & (g2 . I) `1 <= 1 )
proof
reconsider s0 =
(g . O) `1 as
Real ;
A30:
(g2 . O) `1 = (((s0 - b) + (s0 - b)) - (a - b)) / (b - a)
a - b <= s0 - b
by A1, XREAL_1:11;
then
(a - b) + (a - b) <= (s0 - b) + (s0 - b)
by XREAL_1:9;
then A31:
((a - b) + (a - b)) - (a - b) <= ((s0 - b) + (s0 - b)) - (a - b)
by XREAL_1:11;
A32:
(a - b) / (b - a) =
(- (b - a)) / (b - a)
.=
- ((b - a) / (b - a))
.=
- 1
by A2, XCMPLX_1:60
;
b - b >= s0 - b
by A1, XREAL_1:11;
then
(0 + (b - b)) - (a - b) >= ((s0 - b) + (s0 - b)) - (a - b)
by XREAL_1:11;
then A33:
(b - a) / (b - a) >= (((s0 - b) + (s0 - b)) - (a - b)) / (b - a)
by A2, XREAL_1:74;
reconsider s1 =
(g . I) `1 as
Real ;
A34:
(g2 . I) `1 = (((s1 - b) + (s1 - b)) - (a - b)) / (b - a)
a - b <= s1 - b
by A1, XREAL_1:11;
then
(a - b) + (a - b) <= (s1 - b) + (s1 - b)
by XREAL_1:9;
then A35:
((a - b) + (a - b)) - (a - b) <= ((s1 - b) + (s1 - b)) - (a - b)
by XREAL_1:11;
b - b >= s1 - b
by A1, XREAL_1:11;
then
(0 + (b - b)) - (a - b) >= ((s1 - b) + (s1 - b)) - (a - b)
by XREAL_1:11;
then
(b - a) / (b - a) >= (((s1 - b) + (s1 - b)) - (a - b)) / (b - a)
by A2, XREAL_1:74;
hence
(
- 1
<= (g2 . O) `1 &
(g2 . O) `1 <= 1 &
- 1
<= (g2 . I) `1 &
(g2 . I) `1 <= 1 )
by A2, A30, A31, A32, A33, A34, A35, XREAL_1:74;
:: thesis: verum
end;
A36:
now assume
rng f2 meets K0
;
:: thesis: contradictionthen consider x being
set such that A37:
(
x in rng f2 &
x in K0 )
by XBOOLE_0:3;
reconsider q =
x as
Point of
(TOP-REAL 2) by A37;
consider p being
Point of
(TOP-REAL 2) such that A38:
(
p = q &
- 1
< p `1 &
p `1 < 1 &
- 1
< p `2 &
p `2 < 1 )
by A37;
consider z being
set such that A39:
(
z in dom f2 &
x = f2 . z )
by A37, FUNCT_1:def 5;
reconsider u =
z as
Point of
I[01] by A39;
reconsider t =
f . u as
Point of
(TOP-REAL 2) ;
A40:
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . t = |[(((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))))]|
by Def2;
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . t = p
by A38, A39, FUNCT_1:22;
then A41:
(
- 1
< ((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) &
((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) < 1 &
- 1
< ((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) &
((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) < 1 )
by A38, A40, EUCLID:56;
A42:
((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) = ((2 * ((t `1 ) - b)) - (a - b)) / (b - a)
then
(- 1) * (b - a) < (((2 * ((t `1 ) - b)) - (a - b)) / (b - a)) * (b - a)
by A2, A41, XREAL_1:70;
then
(- 1) * (b - a) < (2 * ((t `1 ) - b)) - (a - b)
by A2, XCMPLX_1:88;
then
((- 1) * (b - a)) + (a - b) < ((2 * ((t `1 ) - b)) - (a - b)) + (a - b)
by XREAL_1:10;
then
(2 * (a - b)) / 2
< (2 * ((t `1 ) - b)) / 2
by XREAL_1:76;
then A43:
a < t `1
by XREAL_1:11;
1
* (b - a) > (((2 * ((t `1 ) - b)) - (a - b)) / (b - a)) * (b - a)
by A2, A41, A42, XREAL_1:70;
then
1
* (b - a) > (2 * ((t `1 ) - b)) - (a - b)
by A2, XCMPLX_1:88;
then
(1 * (b - a)) + (a - b) > ((2 * ((t `1 ) - b)) - (a - b)) + (a - b)
by XREAL_1:10;
then
0 / 2
> (((t `1 ) - b) * 2) / 2
;
then A44:
0 + b > t `1
by XREAL_1:21;
A45:
((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) =
(((t `2 ) * 2) / (d - c)) + (1 - ((2 * d) / (d - c)))
.=
(((t `2 ) * 2) / (d - c)) + (((d - c) / (d - c)) - ((2 * d) / (d - c)))
by A3, XCMPLX_1:60
.=
(((t `2 ) * 2) / (d - c)) + (((d - c) - (2 * d)) / (d - c))
.=
(((t `2 ) * 2) + ((d - c) - (2 * d))) / (d - c)
.=
((2 * ((t `2 ) - d)) - (c - d)) / (d - c)
;
then
(- 1) * (d - c) < (((2 * ((t `2 ) - d)) - (c - d)) / (d - c)) * (d - c)
by A3, A41, XREAL_1:70;
then
(- 1) * (d - c) < (2 * ((t `2 ) - d)) - (c - d)
by A3, XCMPLX_1:88;
then
((- 1) * (d - c)) + (c - d) < ((2 * ((t `2 ) - d)) - (c - d)) + (c - d)
by XREAL_1:10;
then
(2 * (c - d)) / 2
< (2 * ((t `2 ) - d)) / 2
by XREAL_1:76;
then A46:
c < t `2
by XREAL_1:11;
1
* (d - c) > (((2 * ((t `2 ) - d)) - (c - d)) / (d - c)) * (d - c)
by A3, A41, A45, XREAL_1:70;
then
1
* (d - c) > (2 * ((t `2 ) - d)) - (c - d)
by A3, XCMPLX_1:88;
then
(1 * (d - c)) + (c - d) > ((2 * ((t `2 ) - d)) - (c - d)) + (c - d)
by XREAL_1:10;
then
0 / 2
> (((t `2 ) - d) * 2) / 2
;
then
0 + d > t `2
by XREAL_1:21;
hence
contradiction
by A1, A43, A44, A46;
:: thesis: verum end;
now assume
rng g2 meets K0
;
:: thesis: contradictionthen consider x being
set such that A47:
(
x in rng g2 &
x in K0 )
by XBOOLE_0:3;
reconsider q =
x as
Point of
(TOP-REAL 2) by A47;
consider p being
Point of
(TOP-REAL 2) such that A48:
(
p = q &
- 1
< p `1 &
p `1 < 1 &
- 1
< p `2 &
p `2 < 1 )
by A47;
consider z being
set such that A49:
(
z in dom g2 &
x = g2 . z )
by A47, FUNCT_1:def 5;
reconsider u =
z as
Point of
I[01] by A49;
reconsider t =
g . u as
Point of
(TOP-REAL 2) ;
A50:
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . t = |[(((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a)))),(((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))))]|
by Def2;
(AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . t = p
by A48, A49, FUNCT_1:22;
then A51:
(
- 1
< ((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) &
((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) < 1 &
- 1
< ((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) &
((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) < 1 )
by A48, A50, EUCLID:56;
A52:
((2 / (b - a)) * (t `1 )) + (1 - ((2 * b) / (b - a))) =
(((t `1 ) * 2) / (b - a)) + (1 - ((2 * b) / (b - a)))
.=
(((t `1 ) * 2) / (b - a)) + (((b - a) / (b - a)) - ((2 * b) / (b - a)))
by A2, XCMPLX_1:60
.=
(((t `1 ) * 2) / (b - a)) + (((b - a) - (2 * b)) / (b - a))
.=
(((t `1 ) * 2) + ((b - a) - (2 * b))) / (b - a)
.=
((2 * ((t `1 ) - b)) - (a - b)) / (b - a)
;
then
(- 1) * (b - a) < (((2 * ((t `1 ) - b)) - (a - b)) / (b - a)) * (b - a)
by A2, A51, XREAL_1:70;
then
(- 1) * (b - a) < (2 * ((t `1 ) - b)) - (a - b)
by A2, XCMPLX_1:88;
then
((- 1) * (b - a)) + (a - b) < ((2 * ((t `1 ) - b)) - (a - b)) + (a - b)
by XREAL_1:10;
then
(2 * (a - b)) / 2
< (2 * ((t `1 ) - b)) / 2
by XREAL_1:76;
then A53:
a < t `1
by XREAL_1:11;
1
* (b - a) > (((2 * ((t `1 ) - b)) - (a - b)) / (b - a)) * (b - a)
by A2, A51, A52, XREAL_1:70;
then
1
* (b - a) > (2 * ((t `1 ) - b)) - (a - b)
by A2, XCMPLX_1:88;
then
(1 * (b - a)) + (a - b) > ((2 * ((t `1 ) - b)) - (a - b)) + (a - b)
by XREAL_1:10;
then
0 / 2
> (((t `1 ) - b) * 2) / 2
;
then A54:
0 + b > t `1
by XREAL_1:21;
A55:
((2 / (d - c)) * (t `2 )) + (1 - ((2 * d) / (d - c))) =
(((t `2 ) * 2) / (d - c)) + (1 - ((2 * d) / (d - c)))
.=
(((t `2 ) * 2) / (d - c)) + (((d - c) / (d - c)) - ((2 * d) / (d - c)))
by A3, XCMPLX_1:60
.=
(((t `2 ) * 2) / (d - c)) + (((d - c) - (2 * d)) / (d - c))
.=
(((t `2 ) * 2) + ((d - c) - (2 * d))) / (d - c)
.=
((2 * ((t `2 ) - d)) - (c - d)) / (d - c)
;
then
(- 1) * (d - c) < (((2 * ((t `2 ) - d)) - (c - d)) / (d - c)) * (d - c)
by A3, A51, XREAL_1:70;
then
(- 1) * (d - c) < (2 * ((t `2 ) - d)) - (c - d)
by A3, XCMPLX_1:88;
then
((- 1) * (d - c)) + (c - d) < ((2 * ((t `2 ) - d)) - (c - d)) + (c - d)
by XREAL_1:10;
then
(2 * (c - d)) / 2
< (2 * ((t `2 ) - d)) / 2
by XREAL_1:76;
then A56:
c < t `2
by XREAL_1:11;
1
* (d - c) > (((2 * ((t `2 ) - d)) - (c - d)) / (d - c)) * (d - c)
by A3, A51, A55, XREAL_1:70;
then
1
* (d - c) > (2 * ((t `2 ) - d)) - (c - d)
by A3, XCMPLX_1:88;
then
(1 * (d - c)) + (c - d) > ((2 * ((t `2 ) - d)) - (c - d)) + (c - d)
by XREAL_1:10;
then
0 / 2
> (((t `2 ) - d) * 2) / 2
;
then
0 + d > t `2
by XREAL_1:21;
hence
contradiction
by A1, A53, A54, A56;
:: thesis: verum end;
then
rng f2 meets rng g2
by A1, A12, A13, A18, A19, A20, A21, A22, A29, A36, Th52;
then A57:
(rng f2) /\ (rng g2) <> {}
by XBOOLE_0:def 7;
consider y being Element of (rng f2) /\ (rng g2);
A58:
( y in rng f2 & y in rng g2 )
by A57, XBOOLE_0:def 4;
then consider x being set such that
A59:
( x in dom f2 & y = f2 . x )
by FUNCT_1:def 5;
A60:
y = (AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (f . x)
by A59, FUNCT_1:22;
consider x2 being set such that
A61:
( x2 in dom g2 & y = g2 . x2 )
by A58, FUNCT_1:def 5;
A62:
y = (AffineMap (2 / (b - a)),(1 - ((2 * b) / (b - a))),(2 / (d - c)),(1 - ((2 * d) / (d - c)))) . (g . x2)
by A61, FUNCT_1:22;
dom f2 c= dom f
by RELAT_1:44;
then A63:
f . x in rng f
by A59, FUNCT_1:12;
dom g2 c= dom g
by RELAT_1:44;
then A64:
g . x2 in rng g
by A61, FUNCT_1:12;
then
f . x = g . x2
by A6, A9, A60, A62, A63, FUNCT_1:def 8;
then
(rng f) /\ (rng g) <> {}
by A63, A64, XBOOLE_0:def 4;
hence
rng f meets rng g
by XBOOLE_0:def 7; :: thesis: verum