text: 
  interface 
  
     double precision function ppnd (p, ifault)
       implicit none
       double precision p
       integer ifault
     end function ppnd
  
     subroutine normp(x, p, q, pdf)
       implicit none
       double precision x,p,q,pdf
     end subroutine normp
  
     subroutine sortrx(n,data,index)
       implicit none
       integer n
       double precision, intent(in) :: data(n)
       integer, intent(out) :: index(n)
     end subroutine sortrx
  
     double precision function betain(x, p, q, beta, ifault)
       implicit none
       double precision x,p,q,beta,alpha
       integer ifault
     end function betain
  
     double precision function xinbta(p,q,beta,alpha,ifault)
       implicit none
       double precision p,q,beta,alpha
       integer ifault
     end function xinbta
  
     double precision function alngam(xvalue, ifault)
       implicit none
       double precision xvalue
       integer ifault
     end function alngam
  
  end interface
  