!>
!> DSLECT returns .TRUE. if the eigenvalue ZR+sqrt(-1)*ZI is to be
!> selected, and otherwise it returns .FALSE.
!> It is used by DCHK41 to test if DGEES successfully sorts eigenvalues,
!> and by DCHK43 to test if DGEESX successfully sorts eigenvalues.
!>
!> The common block /SSLCT/ controls how eigenvalues are selected.
!> If SELOPT = 0, then DSLECT return .TRUE. when ZR is less than zero,
!> and .FALSE. otherwise.
!> If SELOPT is at least 1, DSLECT returns SELVAL(SELOPT) and adds 1
!> to SELOPT, cycling back to 1 at SELMAX.
!> 

ZR

!>          ZR is DOUBLE PRECISION
!>          The real part of a complex eigenvalue ZR + i*ZI.
!> 

ZI

!>          ZI is DOUBLE PRECISION
!>          The imaginary part of a complex eigenvalue ZR + i*ZI.
!> 

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