A possible law

You could formalise your idea as the Antaintelligence Generalisation Law:

As antaintelligence increases, it progressively develops, recruits, and integrates a broader range of cognitive capacities, causing general intelligence to increase at a greater rate than antaintelligence itself.

More strongly:

The general-intelligence yield per unit increase in antaintelligence increases with the existing extent of antaintelligence.

Let the antageneralisation factor be:

\[ F_{AG}=\frac{\Delta G}{\Delta A} \]

where \(F_{AG}\) measures the increase in general intelligence produced per unit increase in antaintelligence.

Your claim would be:

\[ F_{AG}>1 \]

and potentially:

\[ \frac{dF_{AG}}{dA}>0 \]

Meaning that the antageneralisation factor itself increases as antaintelligence increases.