Attach identifying tag to LMIs
tag = newlmi
newlmi adds a new LMI to the LMI system currently described and returns an identifier tag for this LMI. This identifier can be used in
dellmi commands to refer to the newly declared LMI. Tagging LMIs is optional and only meant to facilitate code development and readability.
Identifiers can be given mnemonic names to help keep track of the various LMIs. Their value is simply the ranking of each LMI in the system (in the order of declaration). They prove useful when some LMIs are deleted from the LMI system. In such cases, the identifiers are the safest means of referring to the remaining LMIs.