Surjectivity of functors on grammars

An Observation on Relative Parsing Time

“…We now mention a proposition for which the unambiguity restriction is no longer needed [6,14,23]. As a matter of fact, we might even neglect the length-preserving condition.…”

“…Theorem 3 was first presented by Hotz [14], and served as a motivation for the research documented in [5,6,15,21,23]. THEOREM 3.…”

“…In [23] it is used to provide a test for strong equivalence similar to [17,18,20]. Theorems for non-length-preserving maps are found in [6,22]. Furthermore, a straightforward construction will convert the automaton into a machine with output which will produce one co-image derivation in time cn~, if any exist, or else print an error message.…”