(794 ) 
We can however regard in this case of exception the domain yz, 
as belonging to a set of domains G,,, whose character is that of a 
domain y,, not being in that case of exception, on whose boundary 
in one or more points or arcs an inner are of /, and an inner are 
of i, touch each other without intersecting each other. An example 
is given in fig. 5, where y,, with y',, and y",, composes the indicated 
set of domains G,,. 
%, 
Fig. 5. 
In the same way as for a domain y, we can define for a G, the 
row of signs and the reduced row of signs. 
For values of a preceding «,‚ and converging to a, the boundary 
of y. converges uniformly to that of G.,, and for a certain segment 
of values a preceding a, the reduced row of signs of yz is the same 
as that corresponding to Gz, 
The end we have in view is to prove that we can choose the 
successive domains y, in such a way, that for not one of those domains 
the reduced row of signs becomes pd. 
If £,, and #,, strike against each other on their outside, then we 
have for y., only one choice, for which the row of signs is pp 
(or dd) and the reduced row of signs zero, thus not pd. 
If k, lies entirely on or inside X',,, then there is among the choices 
possible for y., certainly one whose row of signs is either pp 
