These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] sci-mathematics/cadical-3.0.0:0/3.0.0::gentoo  866 KiB
[ebuild  N     ] sci-mathematics/lean-4.24.0:0/4::gentoo  USE="-debug -source" 45348 KiB

Total: 2 packages (2 new), Size of downloads: 46213 KiB