program exf3a  ! all about numeric declarations
  implicit none
  integer, parameter :: float = selected_real_kind(6,30)
  integer, parameter :: double = selected_real_kind(15,300)
  real (kind=float) :: x = 0.5_float
  real*4 :: xx = 0.5                    ! float
  real (kind=double) :: y = 0.5_double
  real*8 :: yy = 0.5                    ! double
  double precision :: yyy = 0.5
  integer (kind=selected_int_kind(2)) :: shortshort = 127
  integer (kind=selected_int_kind(4)) :: short = 32767
  integer (kind=selected_int_kind(8)) :: long = (2**30-1)+2**30   ! won't take 2**31-1
  integer :: k = (2**30-1)+2**30   ! won't take 2**31-1
  integer*8 :: kk = 2**30          ! won't take 2**60
  kk = kk + kk
  kk = kk + kk
  kk = kk + kk
  kk = kk + kk
  kk = 4*kk      ! 2**38  but not at compile time
  
  print *, "exf3a.f90 all about numeric declarations"
  print *, "real information"
  print *, "kind(x)=", kind(x), "  kind(y)=", kind(y)
  print *, "kind(xx)=", kind(xx), "  kind(yy)=", kind(yy)
  print *, "kind(yyy)=", kind(yyy)
  print *, "digits x,y", digits(x), digits(y)
  print *, "digits xx,yy", digits(xx), digits(yy)
  print *, "digits yyy", digits(yyy)
  print *, "epsilon x,y", epsilon(x), epsilon(y)
  print *, "epsilon xx,yy", epsilon(xx), epsilon(yy)
  print *, "epsilon yyy", epsilon(yyy)
  print *, "huge x,y", huge(x), huge(y)
  print *, "huge xx,yy", huge(xx), huge(yy)
  print *, "huge yyy",  huge(yyy)
  print *, "maxexponent x,y", maxexponent(x), maxexponent(y)
  print *, "minexponent x,y", minexponent(x), minexponent(y)
  print *, "precision x,y", precision(x), precision(y)
  print *, "radix x,y", radix(x), radix(y)
  print *, "range x,y", range(x), range(y)
  print *, "tiny x,y", tiny(x), tiny(y)
  print *, "sin(x),sin(y)", sin(x), sin(y)
  print *, "integer information"
  print *, "kind(shortshort)=", kind(shortshort), shortshort
  print *, "kind(short)=", kind(short), short
  print *, "kind(long)=", kind(long), long
  print *, "kind(k)=", kind(k), k
  print *, "kind(kk)=", kind(kk), kk
end program exf3a