In the centre of this Indus sign, there is a road. Four tracks converge on the road, one from each of the cardinal points. The converging routes are surrounded by four points of darkness. Each
point of darkness signifies that something is false. Hence, the image is false for each direction, in other words, it is not possible. It follows that this is an ideograph for cannot access.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-655 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 27: Collections in Pakistan: Suomalainen Tiedeakatemia.