gap(s)
- fire ash carbon gone
- nothing none empty not
- theory of null numbers
- vacant absent zero space
- theory of sparse matrix
- an absence
- exponential decline
- crash .
- holes in the matrix
- gap(s) ...
- column row
- moth hole black hole
- space silence fact
- theory of null values
- silence of null values
- neon vacant blinking light
- empty storm-drain alley