[NTG-context] How to achieve a LaTeX-center-like thing

Hi, I'd like to have something like this: Let $X$ be a~real Banach space, $D$~an open subset of~$X$ containing~$0$ and $T$ a~continuous mapping from $\overbar{D}$ to~$X$. We say that $T$ satisfies the {\em Mönch condition} if the following implication holds: \blank[small] \startalignment[middle] If $C\subset\overbar{D}$ is countable and $C\subset\clconv\bigl(\{0\}\cup F(C)\bigr)$, then $\overbar{C}$ is compact. \stopalignment \blank[small] Is there any option for alignment which would enable me not to put the blanks manually? TIA, -- Marcin Borkowski http://mbork.pl