set X = dom f1;
set X1 = dom f2;
consider s being real number such that
A9:
( 0 < s & ( for x1, x2 being real number st x1 in dom f1 & x2 in dom f1 holds
abs ((f1 . x1) - (f1 . x2)) <= s * (abs (x1 - x2)) ) )
by XDef3;
consider g being real number such that
A10:
( 0 < g & ( for x1, x2 being real number st x1 in dom f2 & x2 in dom f2 holds
abs ((f2 . x1) - (f2 . x2)) <= g * (abs (x1 - x2)) ) )
by XDef3;
consider x1 being real number such that
A11:
for r being set st r in dom f1 holds
abs (f1 . r) <= x1
by RFUNCT_1:89;
consider x2 being real number such that
A12:
for r being set st r in dom f2 holds
abs (f2 . r) <= x2
by RFUNCT_1:89;
now take p =
(((abs x1) * g) + ((abs x2) * s)) + 1;
:: thesis: ( 0 < p & ( for y1, y2 being real number st y1 in dom (f1 (#) f2) & y2 in dom (f1 (#) f2) holds
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= p * (abs (y1 - y2)) ) )
(
0 <= abs x1 &
0 <= abs x2 )
by COMPLEX1:132;
hence
0 < p
by A9, A10;
:: thesis: for y1, y2 being real number st y1 in dom (f1 (#) f2) & y2 in dom (f1 (#) f2) holds
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= p * (abs (y1 - y2))let y1,
y2 be
real number ;
:: thesis: ( y1 in dom (f1 (#) f2) & y2 in dom (f1 (#) f2) implies abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= p * (abs (y1 - y2)) )assume A19:
(
y1 in dom (f1 (#) f2) &
y2 in dom (f1 (#) f2) )
;
:: thesis: abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= p * (abs (y1 - y2))then
(
y1 in (dom f1) /\ (dom f2) &
y2 in (dom f1) /\ (dom f2) )
by VALUED_1:def 4;
then A20:
(
y1 in dom f1 &
y1 in dom f2 &
y2 in dom f1 &
y2 in dom f2 )
by XBOOLE_0:def 4;
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) =
abs (((f1 . y1) * (f2 . y1)) - ((f1 (#) f2) . y2))
by VALUED_1:5
.=
abs ((((f1 . y1) * (f2 . y1)) + (((f1 . y1) * (f2 . y2)) - ((f1 . y1) * (f2 . y2)))) - ((f1 . y2) * (f2 . y2)))
by VALUED_1:5
.=
abs (((f1 . y1) * ((f2 . y1) - (f2 . y2))) + (((f1 . y1) - (f1 . y2)) * (f2 . y2)))
;
then A21:
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= (abs ((f1 . y1) * ((f2 . y1) - (f2 . y2)))) + (abs (((f1 . y1) - (f1 . y2)) * (f2 . y2)))
by COMPLEX1:142;
A22:
abs ((f1 . y1) * ((f2 . y1) - (f2 . y2))) = (abs (f1 . y1)) * (abs ((f2 . y1) - (f2 . y2)))
by COMPLEX1:151;
0 <= abs ((f2 . y1) - (f2 . y2))
by COMPLEX1:132;
then A24:
abs ((f1 . y1) * ((f2 . y1) - (f2 . y2))) <= (abs x1) * (abs ((f2 . y1) - (f2 . y2)))
by A22, A13, A19, XREAL_1:66;
0 <= abs x1
by COMPLEX1:132;
then
(abs x1) * (abs ((f2 . y1) - (f2 . y2))) <= (abs x1) * (g * (abs (y1 - y2)))
by A10, A20, XREAL_1:66;
then A25:
abs ((f1 . y1) * ((f2 . y1) - (f2 . y2))) <= ((abs x1) * g) * (abs (y1 - y2))
by A24, XXREAL_0:2;
A26:
abs (((f1 . y1) - (f1 . y2)) * (f2 . y2)) = (abs (f2 . y2)) * (abs ((f1 . y1) - (f1 . y2)))
by COMPLEX1:151;
0 <= abs ((f1 . y1) - (f1 . y2))
by COMPLEX1:132;
then A28:
abs (((f1 . y1) - (f1 . y2)) * (f2 . y2)) <= (abs x2) * (abs ((f1 . y1) - (f1 . y2)))
by A26, A13, A19, XREAL_1:66;
0 <= abs x2
by COMPLEX1:132;
then
(abs x2) * (abs ((f1 . y1) - (f1 . y2))) <= (abs x2) * (s * (abs (y1 - y2)))
by A9, A20, XREAL_1:66;
then
abs (((f1 . y1) - (f1 . y2)) * (f2 . y2)) <= (abs x2) * (s * (abs (y1 - y2)))
by A28, XXREAL_0:2;
then
(abs ((f1 . y1) * ((f2 . y1) - (f2 . y2)))) + (abs (((f1 . y1) - (f1 . y2)) * (f2 . y2))) <= (((abs x1) * g) * (abs (y1 - y2))) + (((abs x2) * s) * (abs (y1 - y2)))
by A25, XREAL_1:9;
then A29:
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= (((abs x1) * g) + ((abs x2) * s)) * (abs (y1 - y2))
by A21, XXREAL_0:2;
0 <= abs (y1 - y2)
by COMPLEX1:132;
then
((((abs x1) * g) + ((abs x2) * s)) * (abs (y1 - y2))) + 0 <= ((((abs x1) * g) + ((abs x2) * s)) * (abs (y1 - y2))) + (1 * (abs (y1 - y2)))
by XREAL_1:9;
hence
abs (((f1 (#) f2) . y1) - ((f1 (#) f2) . y2)) <= p * (abs (y1 - y2))
by A29, XXREAL_0:2;
:: thesis: verum end;
hence
for b1 being PartFunc of REAL ,REAL st b1 = f1 (#) f2 holds
b1 is Lipschitzian
by XDef3; :: thesis: verum