C*	CHECK UNDEFINED VARIABLES  -  UNDCHK
C
      SUBROUTINE CHECK(KL)
      BYTE STRING,ISTR,VAR,IB,VARS(8)
      COMMON STRING(660),ISTR(660),VAR(6),NV
      COMMON/EQUIV/ IEQG, IEQDEF, IEQARR(30)	! 24-JUN-79
      COMMON/ISUBC/ ISUBC
      DATA NOUT/6/,NVAR/3/
      DATA IB/1H /
1000  FORMAT(1X,6A1)
1020  FORMAT(1X, 'NV = ', I4)
C     WRITE(NOUT,1022) ISUBC
D1022 FORMAT('0', 'SUBROUTINE CHECK (ISUBC): ', I2)
      L=KL+1
      IF (L.GT.6) GO TO 20
      DO 10 K=L,6
      VAR(K)=IB
10    CONTINUE
20    CONTINUE
C     WRITE (6,1000) VAR
C     WRITE(NOUT,1020) NV
C     IF (NV .EQ. 0) STOP 'NV = 0'
      DO 40 N=1,NV
      READ (NVAR'N) VARS, ISUB, IEQ
      DO 30 K=1,6
      IF (VAR(K).NE.VARS(K)) GO TO 40
30    CONTINUE
C
C	TEST IF VARIABLE APPEARED IN CALL OR ENTRY STATEMENT
      IF (ISUBC .NE. 1) GOTO 31			! ADDED 27-JUN-79
C	YES, REWRITE RECORD WITH ISUBC=1, EXIT FROM ROUTINE
      WRITE(NVAR'N) VARS, ISUBC, IEQ
      GOTO 80
   31 CONTINUE
C	WRITE(NOUT,1030) VAR, ISUB, IEQ
D1030	FORMAT(' ', 5X, 'SUBROUTINE CHECK (VAR,ISUB,IEQ): ', 6A1,2I3)
	IF (IEQ .EQ. 0) GO TO 50		! 24-JUN-79
C
C	   VARIABLE DEFINED BELONGS TO EQUIVALENCE GROUP "IEQ"
C	   IF A VARIABLE IN THIS GROUP HAS NOT BEEN PREVIOUSLY
C	   DEFINED, ADD "IEQ" TO IEQARR
	IF (IEQDEF .EQ. 0) GOTO 35
	DO 32 II = 1,IEQDEF
	IF (IEQARR(II) .EQ. IEQ) GOTO 50
   32	CONTINUE
   35	IEQDEF = IEQDEF + 1		! NOT PREVIOUSLY DEFINED
	IEQARR(IEQDEF) = IEQ
      GO TO 50
40    CONTINUE
      GO TO 80
50    NS=N+1
      IF (NS.GT.NV) GO TO 70
      DO 60 NN=NS,NV
      READ (NVAR'NN) VARS, ISUB, IEQ
      WRITE (NVAR'N) VARS, ISUB, IEQ
      N=N+1
60    CONTINUE
70    NV=NV-1
80    KL=0
      IF (NV.EQ.0) KL=-1
      ISUBC = 0
      RETURN
      END