# How to write centered multi-line conclusion in inference rule?

I'm using the semantic package to write inference rules and I have trouble with the following:

\usepackage[inference]{semantic}
\usepackage{amsmath}

\inference{ expr }{ \begin{aligned} long_expr1 \\ long_expr2 \end{aligned} }


In this code, I want long_expr1 and long_expr2 to be centered. However, the aligned environment aligns them on the right. How can I fix this?

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$$\inference{ expr }{ \begin{gathered} long_expr1 \\ long_expr2 \end{gathered} }$$