! *** PREDECLARED TYPES
     
      %IF %DECLARED ( %BASIC$QUADWORD_DECLARED ) = 0 %THEN
         RECORD BASIC$QUADWORD
            LONG FILL ( 2 )
         END RECORD
         %LET %BASIC$QUADWORD_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$OCTAWORD_DECLARED ) = 0 %THEN
         RECORD BASIC$OCTAWORD
            LONG FILL ( 4 )
         END RECORD
         %LET %BASIC$OCTAWORD_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$HFLOAT_AXP_DECLARED ) = 0 %THEN
         RECORD BASIC$HFLOAT_AXP
            LONG FILL ( 4 )
         END RECORD
         %LET %BASIC$HFLOAT_AXP_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$F_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$F_FLOATING_COMPLEX
            SINGLE REAL_PART
            SINGLE IMAGINARY_PART
         END RECORD
         %LET %BASIC$F_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$D_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$D_FLOATING_COMPLEX
            DOUBLE REAL_PART
            DOUBLE IMAGINARY_PART
         END RECORD
         %LET %BASIC$D_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$G_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$G_FLOATING_COMPLEX
            GFLOAT REAL_PART
            GFLOAT IMAGINARY_PART
         END RECORD
         %LET %BASIC$G_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$H_FLOAT_AXP_CMPLX_DCL ) = 0 %THEN
         RECORD BASIC$H_FLOATING_COMPLEX_AXP
            BASIC$HFLOAT_AXP REAL_PART
            BASIC$HFLOAT_AXP IMAGINARY_PART
         END RECORD
         %LET %BASIC$H_FLOAT_AXP_CMPLX_DCL = 1
      %END %IF
    
    
    ! 
    !          definitions for all xabs
    !                 $xabdef
    ! 
    !   the first four fields are shared in common between all xabs
    !   and hence are defined only once
    !   (the only exception is that the spare word may be used by some xabs)
    ! 
      DECLARE LONG CONSTANT XAB$S_XABDEF = 20
      record XABDEF
         BYTE XAB$B_COD                     !  xab id code
         BYTE XAB$B_BLN                     !  block length
         WORD XABDEF$$_FILL_1               !  (spare)
         LONG XAB$L_NXT                     !  xab chain link
         WORD XAB$W_RVN
         WORD XABDEF$$_FILL_2
         group XAB$R_RDT_OVERLAY
            variant
               case
                  BASIC$QUADWORD XAB$Q_RDT
               case
                  group XAB$R_RDT_FIELDS
                     LONG XAB$L_RDT0
                     LONG XAB$L_RDT4
    ! COMMON AMONG DAT AND RDT XABS
                  end group XAB$R_RDT_FIELDS
            end variant
         end group XAB$R_RDT_OVERLAY
      end record XABDEF
    
      DECLARE LONG CONSTANT XAB$S_XABDEF1 = 23
      record XABDEF1
         BYTE XABDEF$$_FILL_3 ( 1 to 8 )
         BYTE XABDEF$$_FILL_4               ! THESE FIELDS WILL BE DEFINED LATER
         BYTE XABDEF$$_FILL_5
         WORD XABDEF$$_FILL_6
         LONG XABDEF$$_FILL_7
         LONG XABDEF$$_FILL_8
         WORD XABDEF$$_FILL_9
         BYTE XAB$B_BKZ                     ! COMMON TO FHC AND ALQ XABS
      end record XABDEF1
    
      DECLARE LONG CONSTANT XAB$C_CXT_VER1 = 1  !  RMS Context Extraction version 1