From root: Why no mathematical symbols?
What do the arrows mean?
The blog uses two main arrow types in all of the colours.
Solid arrow tips are used for both concept relationships and motion of data.
Hollow arrow tips are used to indicate meaning and provide more context in diagrams.
References and further reading
Bertin, Jacques. 1983. Semiology of Graphics: Diagrams, Networks, Maps. University of Wisconsin Press.
Hardwick, Robert J. 2026. “What do the colours mean?” umbralcalculations, November. https://umbralcalc.github.io/posts/what_do_the_colours_mean.html.
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