*
* $Id$
*
* $Log$
*
*
* xalgdata.inc
*
*CMZ :  3.00/00 02/05/2001  20.42.25  by  Unknown
*-- Author :
*-----------------------------------------------------------------------
*   ALGDAT - Common block containing the executable statements for the
*            evaluation of symbolic expressions.
*   VARIABLES : INS(I, . ) : List of instructions, the first element is
*                            a register address (in case of a normal
*                            operation) or a function descriptor, the
*                            second is the operator, the third an addres
*                            and the fourth the address of the result.
*               NINS       : Number of instructions in INS.
*               REG(I)     : Contents of register I, REG(0)=0, REG(-1)=1
*                            and REG(-2)=2, REG(-3)=pi.
*               NREG       : Number of registers in use.
*               EXEC(I)    : .TRUE. if instruction I is to be executed.
*               NERR       : Number of errors since last call to ALGPRE.
*               NAERR      : Individual error counts.
*               NRES       : Number of independent results.
*               ALGENT(I,.): Instruction list entry refernce table.
*                            1: reference no, 2: in use 0/1, 3: can be
*                            executed 0/1, 4: sequential 0/1, 5: first
*                            instruction, 6: no of instructions, 7: no
*                            of variables, 8: first constant, 9: no of
*                            constants, 10: no of results.
*               ARGREF(I,1): Modification flag for arguments,
*                            0: modifiable global variable,
*                            1: modifiable non-global variable,
*                            2: non-modifiable global variable,
*                            3: non-modifiable non-global variable.
*               ARGREF(I,2): Origin of each argument.
*               NALGE      : Number of entries in use in ALGENT.
*               ISYNCH     : 0: no check, 1: algebra, 2: procedure
*               LIGUND     : Ignore exponential underflow
*   (Last changed on  3/ 6/97.)
*-----------------------------------------------------------------------