Some Examples 
Example L 
as 
Px 0:8<0 
3 E.(u,@) O; <p 
A , otherwise (9.29) 
z 
magnified part of net W(2,8)=0 (9.30) 
\ 
for a partial sum 
Far ' ] 
212 21 i420 oleg 
YE2(we i+2, Oonse)- Eal poi, Bonsa)— Eol peireQou) + E2( [212i Cow) = \A- OTOP OSL vu(S)Silj) 
\ E. ( Loire Gomse) i Eo(pleire, Gemee) —Eo(ju2ira, ou) + E ol peise,om) = A- A-O-O= O ( 9.32) 
all other elements of the net, but the first one give a contribution of zero 
Bites 
therefore 7(x,y,t)= A cos(#2"( x COS Gaysit Y SiN Gous:) — Hie t) (Sg5s)) 
since there is always some set of four net points such that peieyr>ei 
( re 
and Grue0>Oy (9.34) in the limit (x,y,t)=Acos (4g-x-pst) (9.35) 
Plate XXXIx 
= 35> 
