<s>
Consensus	B-Application
dynamics	I-Application
or	O
agreement	B-Application
dynamics	I-Application
is	O
an	O
area	O
of	O
research	O
lying	O
at	O
the	O
intersection	O
of	O
systems	O
theory	O
and	O
graph	O
theory	O
.	O
</s>
<s>
A	O
major	O
topic	O
of	O
investigation	O
is	O
the	O
agreement	O
or	O
consensus	B-Operating_System
problem	I-Operating_System
in	O
multi-agent	O
systems	O
that	O
concerns	O
processes	O
by	O
which	O
a	O
collection	O
of	O
interacting	O
agents	O
achieve	O
a	O
common	O
goal	O
.	O
</s>
<s>
Other	O
problems	O
are	O
the	O
rendezvous	O
problem	O
,	O
synchronization	O
,	O
flocking	B-Application
,	O
formation	B-Application
control	I-Application
.	O
</s>
<s>
One	O
solution	O
paradigm	O
is	O
distributed	B-Application
constraint	I-Application
reasoning	I-Application
.	O
</s>
