[tex2html_wrap6070] [GENERIC FUNCTION]
Define the special patterns that should be looked for when processing object. Methods on this function for specific object types specify such patterns in the form of a case statement, with one case for each pattern to be identified. Rendering rules that should be applied when special patterns are seen, can be defined. Example: If we specify 'half as the special pattern for [tex2html_wrap6066], then we can define a rendering rule named 'half for object math-object. Activating style use-special-patterns and executing turn-on-special-pattern with argument math-object results in the newly defined rule being used when rendering expressions containing [tex2html_wrap6068]. This function is memoized: it remembers its results between computations.