Autosemantic lexical units are represented by complex nodes in the tectogrammatical trees (the value of their `nodetype`

attribute is `complex`

; see Section 7, "Complex nodes"). Complex nodes have a t-lemma, grammatemes and other attributes. (Other nodes types have no grammatemes.)

For a great number of complex nodes, their t-lemma is identical to their m-lemma (see Section 1, "Morphological lemma (m-lemma)", Section 2, "The relation between a node's t-lemma and m-lemma and between its t-lemma and word form"). However, in some cases, the t-lemmas differ from their respective m-lemmas. This is mostly caused by the fact that some of the processes of syntactic and lexical derivation are reflected at the tectogrammatical level (see Section 1, "Syntactic and lexical derivation").