It has recently been recognized by the author that the quantum contextuality
paradigm may be formulated in terms of the properties of some subgroups of the
two-letter free group G and their corresponding point-line incidence geometry
G. I introduce a fundamental homomorphism f mapping the
(infinitely many) words of G to the permutations ruling the symmetries of
G. The substructure of f is revealing the essence of geometric
contextuality in a straightforward way.Comment: 18 pages, 11 figures, 2 tables to appear in "Symmetry: Culture and
Science