Update concurrency.md

research/concurrency.md

@@ -17,7 +17,7 @@ We have applied our reasoning to, for example, algorithms for
 manipulating concurrent B-trees, skip lists from
 java.util.concurrent, graph algorithms and the POSIX file system.
 Our goal is to challenge and improve the state-of-the-art in
-concurrent reasoning, refining our logics to deal with more advanved
+concurrent reasoning, refining our logics to deal with more advanced
 concurrent programs, developing automated reasoning tools based on these
 logics, and applying our work to real-world concurrent programs.