Ed invero, 
r+27T AT P2Y PI a+27 97 ada 
f | | f f f(x,y) dedy* |de= f Q(c.,y)de= f o(c, yY)der+ f o(c,y)dae= 
CI 0 “0 <0 < 0 CI 0 e o 
0 2QT7 
9) + f g(27+2,y)dx. 
“o 
Ora, 
g(2r+x,y)= 
f EI f "{f(% dp |ar= {] sa Î f (ry)at | a+ f I f fi (cy)? | 
) “IS; “0 sO ‘9r RORGNNNO 
0 
SS fina ("fi anagan 
0 0 
oa OTO. MELI 
du (YU) +9(0,9), 
e perciò: 
n DT Vers x 7 
P (+27) 09) M)+L (19), AM f ed ff ffemarar, 
0 ESCO PIRA 
9 (4) = | | Sfar : 
0 0 0 
Abbiamo poi 
F(x+27,9+27)=0(4+27)+x01(4+27)+F(2,y+27), 
27 Yy+27 27 Y 
9(y+27)= f o(0,y+27) dx, 0; (+27= fl f Î f(2,y)dygda, 
@ “0 "0 *0 
0 
Yt2IT Pa pY 
o(0,Yy+ 2m=( f [fe y) dy* de= 
2° al e 
0 
-2r Ea y 2744 PL pY DT Y 
{fffenaa( f finnari=(L@Ywy- fer = 
“o 2) “o “or “o DI “0 0 
0 
F Y "D7+-Y x 
x@+f{f f{nacdy)wy= 
© NQ N) 
a Y 97 to) SD tt YI Ho 
x-f| f fremazay+f (fg ardy [ay 
“0 FEB A) 27 “0 
" a Y : y 
+ fue f Lema ATA f Lay, 
‘0 “o “o 
