anchor.diff:     40 CONTINUE
         RETURN
         END
  +
         SUBROUTINE BLDF(N,S,N6,SS,IL,IR,NLR)
   C SUBROUTINE TO EXPLICITLY DETERMINE SET  A1  OR SET  A - A1
   C OR SET  A - A1 - A2  WHEN  LEV .EQ. 1 .
  -      DIMENSION S(N),SS(N6)
  +      use iso_fortran_env
  +      implicit none
  +
  +      integer(int64) :: n,n6,il,ir,nlr
  +      real(real64), DIMENSION (N) :: S
  +      real(real64), DIMENSION (N6) :: SS
  +      integer(int64) :: nn7,ics,icd,ius,ips,iud,ipd
  +      real(real64) :: ap
  +
         NN7 = (IR - IL + 1)/7
         ICS = 1
         ICD = NN7 + 1
  
positive.code:       V(K+1) = IV
        GO TO 100
        END
        end program
  
negative.code:    50 Z = - 3
        RETURN
        END
  
        SUBROUTINE KSMALL(N,S,K,N6,SS)
  C SUBROUTINE TO FIND THE  K-TH  SMALLEST OF  N  ELEMENTS
  C IN  O(N)  TIME.
  