Adequate family of active coordinate sets
ID: adequate-family-of-active-coordinate-sets
For a fixed alphabet size , a family is adequate if every two-color finite coloring of has a monochromatic combinatorial line whose nonempty active coordinate set belongs to .
An intersecting family is never adequate. Color a word red when the coordinates carrying letter contain a member of , and blue otherwise. For a line with active set , its letter- word is red and its letter- word is blue, because no member of an intersecting family can lie wholly outside .
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