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/givaro-4.2.1:0/9::gentoo  USE="-doc -test" 1012 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     ] virtual/lapack-3.10-r1::gentoo  USE="flexiblas -eselect-ldso -index64" 0 KiB
[ebuild  N     ] virtual/blas-3.8-r1::gentoo  USE="flexiblas -eselect-ldso -index64" 0 KiB
[ebuild  N     ] sci-libs/fflas-ffpack-2.5.0-r1::gentoo  USE="openmp" 1073 KiB
[ebuild  N     ] sci-libs/iml-1.0.5-r1::gentoo  383 KiB
[ebuild  N     ] sci-mathematics/flint-3.5.0:0/23::gentoo  USE="-doc -ntl -test" 6226 KiB
[ebuild  N     ] sci-libs/linbox-1.7.1::gentoo  USE="openmp -doc -opencl" 2252 KiB

Total: 15 packages (15 new), Size of downloads: 127554 KiB