> Also where does text end and diagrams/images start?
Text is the written form of language. And language is defined as a sequence of symbols. Thus, text is a subset of diagrams. Arbitrary diagrams can be of any topology (e.g. DAGs or even have cycles), however text always is of sequential topology (or a hierarchy as there is an isomorphic mapping to sequences).
Basically, if there is a canonical way of reading it out loud, then it has an explicit sequence and is thus text.
By that rule it follows that:
Musical notation is text as it is strictly sequential (in time) and maybe hierarchical if there are multiple tracks. Most mathematical notations are text, as they are also sequential, even matrices are only a hierarchy of sequences which in turn can be serialized. Chemical / molecular diagrams are not text, they can contain cycles. Same goes for electronic and logic circuit schematics or rail way diagrams found in public transportation.
> Similarly the example about the Wikipedia text of human rights being supposedly impossible to convey via image
Schematics and diagrams are only use full if / because they are subject to a certain defined visual vocabulary. So if you had a visual vocabulary in that domain then you could express them as a diagram.
Text is the written form of language. And language is defined as a sequence of symbols. Thus, text is a subset of diagrams. Arbitrary diagrams can be of any topology (e.g. DAGs or even have cycles), however text always is of sequential topology (or a hierarchy as there is an isomorphic mapping to sequences).
Basically, if there is a canonical way of reading it out loud, then it has an explicit sequence and is thus text.
By that rule it follows that: Musical notation is text as it is strictly sequential (in time) and maybe hierarchical if there are multiple tracks. Most mathematical notations are text, as they are also sequential, even matrices are only a hierarchy of sequences which in turn can be serialized. Chemical / molecular diagrams are not text, they can contain cycles. Same goes for electronic and logic circuit schematics or rail way diagrams found in public transportation.
> Similarly the example about the Wikipedia text of human rights being supposedly impossible to convey via image
Schematics and diagrams are only use full if / because they are subject to a certain defined visual vocabulary. So if you had a visual vocabulary in that domain then you could express them as a diagram.