Test of math formatting.
X ¯ i ( t + Δ t ) = X ¯ i ( t ) = 2 D i Δ t ξ ¯ ( t ) {\displaystyle {\bar {X}}_{i}(t+\Delta t)={\bar {X}}_{i}(t)={\sqrt {2D_{i}\Delta t}}{\bar {\xi }}(t)}
End of test.
