Text unit is either word or phrase.
Text concept can be easily transformed into piece of text through word dictionary or phrase dictionary.
“Cow” is a text concept (because it’s a word).
“Red neck” is a text concept (because it’s a phrase).
Every text concept, as any other concept is stored in the main memory.
Text concept is a surface concept, because it has direct connection to the world (through word and phrase dictionaries).
Text pairs keep information about usual order or text concepts in a text.