anchor.diff:  ET,1,PLANE183,0,,2      ! Quadratic plane strain quadrilaterals 
   ET,2,PLANE183,1,,2      ! Quadratic plane strain triangles
   ET,3,CONTA172
  +KEYOPT, 3, 1, 0
  +KEYOPT, 3, 2, 0
   
   ALLSEL
   
  
positive.code: 
  LSEL,S,LINE,,18
  NSLL,S,1
  TYPE,2
  ESURF
  
  LSEL,S,LINE,,19
  NSLL,S,1
  TYPE,2
  ESURF
  
  FINISH              ! Finish pre-processing
  
negative.code:    MP,GXZ,2,GLT      ! mp,Poisson's ratio,material number,value
  *ENDIF
  
  MP,MU,3,0
  
  ! Assign properties to areas
  ! ASEL, Type, Item, Comp, VMIN, VMAX, VINC, KSWP
  ! AATT, MAT, REAL, TYPE, ESYS, SECN
  