What does this equation mean?

where $g_S$ is the growth rate of human research labor, exactly as before, and $g_C$ is a new term generated by the continuous automation of research tasks — one that can be strictly positive even when $g_S$ is zero, because a fixed number of human researchers can still be automated onto an exponentially shrinking share of remaining, not-yet-automated tasks, concentrating human attention ever more narrowly on the residual problems machines cannot yet touch while machines handle a growing share of the rest [ 6 ] . In plain terms: if enough of what a researcher actually does — running the experiment, searching the literature, proposing the next candidate molecule, checking the math — can be handed to a machine, population no longer has to be the thing that’s growing for the idea-production function to keep growing too. Aghion, Jones, and Jones are explicit that this is one channel among several they model, and that full automation of the idea-production function is a mathematical limiting case — one route, among the several “singularity” scenarios their paper works through formally, to an unbounded growth rate, which they treat as a theoretical possibility to be checked against evidence rather than a forecast [ 6 ] .