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consts\\
\>Ball\>::\ "{}'a\ set\ \mbox{$\Rightarrow$}\ ('a\ \mbox{$\Rightarrow$}\ bool)\ \mbox{$\Rightarrow$}\ bool"{}\\
syntax\\
\>"{}\mbox{$\varepsilon$}Ball"{}\>::\ "{}pttrn\ \mbox{$\Rightarrow$}\ 'a\ set\ \mbox{$\Rightarrow$}\ bool\ \mbox{$\Rightarrow$}\ bool"{}\>\>\>\>\>("{}(3\mbox{$\forall$}\_\mbox{$\in$}\_./\ \_)"{}\ 10)\\
translations\\
\>\>"{}\mbox{$\forall$}x\mbox{$\in$}A.\ P"{}\ \mbox{$=$}\mbox{$=$}\ "{}Ball\ A\ (\mbox{$\lambda$}x.\ P)"{}\\
defs\\
\ \ \ \ \ Ball\_def\>\>"{}Ball\ A\ P\ \mbox{$\equiv$}\ \mbox{$\forall$}x.\ x\mbox{$\in$}A\ \mbox{$\longrightarrow$}\ P\ x"{}\\
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