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|context> => |context: simple sentence to word2sp example>

supported-ops |this> => |op: next-1> + |op: next-2> + |op: next-3> + |op: next-2gram> + |op: next-3gram>
next-1 |this> => |is>
next-2 |this> => |a>
next-3 |this> => |sentence>
next-2gram |this> => |is a>
next-3gram |this> => |is a sentence>

supported-ops |is> => |op: pre-1> + |op: next-1> + |op: next-2> + |op: next-3> + |op: next-2gram> + |op: next-3gram>
pre-1 |is> => |this>
next-1 |is> => |a>
next-2 |is> => |sentence>
next-3 |is> => |about>
next-2gram |is> => |a sentence>
next-3gram |is> => |a sentence about>

supported-ops |a> => |op: pre-2> + |op: pre-1> + |op: pre-2gram> + |op: next-1> + |op: next-2> + |op: next-3> + |op: next-2gram> + |op: next-3gram>
pre-2 |a> => |this>
pre-1 |a> => |is>
pre-2gram |a> => |this is>
next-1 |a> => |sentence>
next-2 |a> => |about>
next-3 |a> => |mary>
next-2gram |a> => |sentence about>
next-3gram |a> => |sentence about mary>

supported-ops |sentence> => |op: pre-3> + |op: pre-2> + |op: pre-3gram> + |op: pre-2gram> + |op: next-1> + |op: next-2> + |op: next-3> + |op: next-2gram> + |op: next-3gram>
pre-3 |sentence> => |a>
pre-2 |sentence> => |is>
pre-3gram |sentence> => |this is a>
pre-2gram |sentence> => |is a>
next-1 |sentence> => |about>
next-2 |sentence> => |mary>
next-3 |sentence> => |and>
next-2gram |sentence> => |about mary>
next-3gram |sentence> => |about mary and>

supported-ops |*> => |op: word2sp-op>
word2sp-op |*> #=> apply(|op: pre-3> + |op: pre-2> + |op: pre-3gram> + |op: pre-2gram> + |op: next-1> + |op: next-2> + |op: next-3> + |op: next-2gram> + |op: next-3gram>,|_self>)

supported-ops |example sentence> => |op: the>
the |example sentence> => |This is a sentence about Mary and her pet dog>
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