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Could somebody help me in figure out what is not working in this code?
Does multicolumn works in tabularx context?
the output should be as the attached file

\documentclass{amsart}
\usepackage{tabularx}
..
\begin{table}[ht]
\begin{center}
\begin{tabularx}{\textwidth}{cXcX}
\toprule
\multicolumn ...