SUBROUTINE  fctfx(  u,  f1,  f2,  p,  u_exact, tps  )
      USE numerics
      IMPLICIT  NONE
      REAL(rp),  DIMENSION(sx-1:ex+1,sy-1:ey+1,sz-1:ez+1),  INTENT(OUT)  ::  u
      REAL(rp),  DIMENSION(sx-1:ex+1,sy-1:ey+1,sz-1:ez+1),  INTENT(OUT)  ::  p
      REAL(rp),  DIMENSION(sx  :ex  ,sy  :ey  ,sz  :ez  ),  INTENT(OUT)  ::  f1
      REAL(rp),  DIMENSION(sx  :ex  ,sy  :ey  ,sz  :ez  ),  INTENT(OUT)  ::  f2
      REAL(rp),  DIMENSION(sx-1:ex+1,sy-1:ey+1,sz-1:ez+1),  INTENT(OUT)  ::  u_exact
      REAL(rp),  INTENT(IN)  ::  tps
      END  SUBROUTINE  fctfx