23. A method as claimed in claim 20 , wherein said grammar is hierarchical and said rules include terminal and/or non-terminal symbols, whereby said rules refer to lower level rules to resolve non-terminal symbols.
23. A method as claimed in claim 20 , wherein said grammar is hierarchical and said rules include terminal and/or non-terminal symbols, whereby said rules refer to lower level rules to resolve non-terminal symbols. 28. A method as claimed in claim 23 , wherein said rules include a hyperparameter representing use of the rule in observations parsed during said grammatical inference.