The Inca system of ceque is built on a mixture of three and four. There are four quarters but the building blocks are of three kinds: 'white', 'black' and 'white/black' (i.e. the result of mixing 'white' with 'black', or in the Easter Island idiom: heu).

The glyph we are studying looks upside down, at least if you think about the legs of Pachamama and the explanation humu by Metoro. I think that is exactly what is intended, because we are at a point of reversal, the change from 'white' to 'black'.

And then, in the Inca mind there are three building blocks. We have three parts here too, not only 'white' (1b-6b) and 'black' (1c-6c) but also (1a-6a). Is 1a-6a = 'white/black'?