I still DO NOT AGREE with these statements:
* "Lemma (plural Lemmas) for use as a human readable representation of the lexeme, e.g. "run" or "when pigs fly".
WRONG. By definition the human readable form is NOT the LEMMA, but the LEXEME by definition (even if it can have different written forms, e.g. for plurals, or mutations, or alternate orthographies with minor differences such as variable accents, or presence/absence of hyphens in compound forms)
* "A Lexeme can have several lemmas, even though it is rare"
The last assertion is completely false: a lexeme VERY FREQUENTLY has multiple lemmas (each lemma however carry a SINGLE sense, by definition!)
* "A list of Senses, describing the different meanings of the lexeme"
The different meanings of the lexeme are given by the list of its lemmas (so I maintain that LEMMA=SENSE)
We have an unnecessary abstraction level (and this is already visible in the interface): this just complicates the model by adding an extra object (meaning it is inefficient to process, requires additional queries, and maintenance).
Lexemes must be at the root of the tree ! Note that a lexeme can contain multiple words for a complete expression or necessary particles, prepositions, postpositions or other terms (like reflective pronouns), e.g. for verbs (notably in English for verbal particles in prefix or suffix, as in "to fill in" which as both, or "se"/"s'" in French, these particles may be agglutinated and muted, detached or reordered elsewhere in the sentence depending on forms or combined with other particles (e.g. in German "hereinkommen"-> "Er kommt herein.", "Für hereinzukommen, ..."), but they keep their semantic meaning.
Forms of lexemes lowever have restrictions of usage: NOT ALL forms are usable for EVERY lemma=sense of the same lexeme (e.g. a lemma=sense would be only valid for some forms and not for others, e.g. plural forms): this is not frequent but not exceptional.
Note as well that some forms (e.g. the plural) may change the grammatical gender or case: a singular noun could be masculine, but its plural feminine (typical example un French: for the same lemma=sense of the lexeme "amour", the form "amour" found in "mon amour" is masculine as a singular noun, but the form "amours" found in "mes amours" i is feminine as a plural noun).
So the real schema is:
LEXEME
* 0. is language specific.
* 1. possibly made of several LEXEMES
* 2. has one or more FORMS
- 2a. the first form is the most generic one (e.g. the singular form if it exists for a noun or adjective ; the present infinitive form if it exists for a verb, because verbs can be defective some some tense, modes). The first form generally carries all grammatical characteristic used by default for all other forms.
- 2b. each additional form can have modifications of the base grammatical classification but generally they inherit them unless they are overridden.
- 2c.
- 2c. some forms may be equivalent to other forms of the same lexeme, so we need one or more REPRESENTATIONS to exhibit them (including in other script systems, such as Latin, Cyrillic, or under different orthographic systems and reforms)
* 3. has one or several LEMMAS=SENSES
3a. each lemma=sense could contain some restrictions on the applicable forms
3b. the lemma has a definition of its sense
3d. the lemma may be valid only in some context (e.g. specialized terminology for a domain) or forbidden/depreciated in other contexts (e.g. slang words, popular/vulgar speech, formal declarations)
3c. the lemma is translatable to one or more lemmas in the target language defined separately within a different lexeme specific to that target language
In all cases, each lemma belongs to a single lexeme.