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

Calculating dependencies ... done!
Dependency resolution took 1.17 s (backtrack: 0/20).

[ebuild  N     ] virtual/fortran-0-r1::gentoo  USE="openmp" 0 KiB
[ebuild  N     ] sci-libs/cddlib-094n::gentoo  USE="-doc -examples -static-libs -tools" 1349 KiB
[ebuild  N     ] dev-libs/gf2x-1.3.0-r1:0/3::gentoo  USE="-custom-tune -fft -static-libs" CPU_FLAGS_X86="pclmul sse2 sse3 sse4_1 ssse3" 711 KiB
[ebuild  N     ] dev-libs/ntl-11.6.0:0/45::gentoo  USE="threads -doc" 2539 KiB
[ebuild  N     ] sci-libs/openblas-0.3.34::gentoo  USE="openmp -cpudetection -index64 -pthread -relapack -test" 24734 KiB
[ebuild  N     ] sci-libs/lapack-3.12.1-r2::gentoo  USE="deprecated flexiblas lapacke -doc -eselect-ldso -index64 -test" 7879 KiB
[ebuild  N     ] sci-libs/flexiblas-3.5.0::gentoo  USE="openblas openmp system-blas -blis -index64 -mkl -tbb -test" 80741 KiB
[ebuild  N     ] sci-libs/blas-lapack-aux-wrapper-6::gentoo  USE="-index64 -test" 10 KiB
[ebuild  N     ] virtual/cblas-3.8-r1::gentoo  USE="flexiblas -eselect-ldso -index64" 0 KiB
[ebuild  N     ] sci-mathematics/flint-3.5.0:0/23::gentoo  USE="-doc -ntl -test" 6226 KiB
[ebuild  N     ] sci-mathematics/singular-4.4.1-r1::gentoo  USE="readline -emacs -examples (-polymake)" 20619 KiB

Total: 11 packages (11 new), Size of downloads: 144803 KiB