Utility functions finding names and types of objects
Arguments
- item
- A LaTeX2item which is an environment 
- value
- A character string to set as the name 
Value
latexTag() returns the LaTeX2 tag for the item or NULL.
catcode() returns the TeX catcode for the item, or NULL.
envName() returns the Latex environment name for an item, or NULL.
macroName() returns the Latex macro, or NULL.