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$C$ $\mid${-} ${\it es}$,${\it in}$,${\it out}$.$P$(${\it es}$;${\it in}$;${\it out}$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=$\forall$$X$:Interface(${\it ds}$;${\it da}$;$A$).\+
\\[0ex]let $R$,$Y$ = ($C$($X$)) in $R$ $\mid${-}${\it es}$.es{-}decl(${\it es}$;${\it ds}$;${\it da}$) $\Rightarrow$ $P$(${\it es}$;[[$X$]];[[$Y$]])
\-
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