C*	WRITE STATEMENT  -  UNDWRI
C
C	A SEARCH IS MADE FOR IMPLIED DO LOOPS SO THAT ALL INDEX
C	VARIABLES USED MAY BE DEFINED
C	E.G.,  IN THE WRITE STATEMENT:
C 	  WRITE(5,1010) (K(L), L = 1,N)
C	THE VARIABLE L IS DEFINED.
C
      SUBROUTINE WC(IEND)
      BYTE STRING,ISTR,VAR
      COMMON STRING(660),ISTR(660),VAR(6)
C	WRITE(6,6010) IEND
C6010	FORMAT('0', 'SUB WC: IEND =', I4)
C	WRITE(6,6020) (ISTR(II), II = 1,IEND)
C6020	FORMAT('0','SUB WC: ISTR   =', 50I1)
C	WRITE(6,6030) (STRING(II), II = 1,IEND)
C6030	FORMAT('0','SUB WC: STRING =', 50A1)
      I=1
      I3=1		! 3 IN ISTR REPRESENTS LEFT PARENTHESES
      I4=0		! 4 IN ISTR REPRESENTS RIGHT PARENTHESES
10    I=I+1
      IF (I.GT.IEND) RETURN
      IF (ISTR(I).EQ.3) I3=I3+1
      IF (ISTR(I).EQ.4) I4=I4+1
      IF (I3.NE.I4) GO TO 10		! L AND R PARENS SHOULD BE 
C					! EQUAL AFTER WRITE(...)
C
C	   WRITE(...) HAS BEEN SCANNED, START ON VARIABLE LIST
C	   SCAN UNTIL '=' HAS BEEN FOUND, OR END OF STATEMENT
20    I=I+1
      IF (I.GT.IEND) RETURN
      IF (ISTR(I).NE.5) GO TO 20	! '=' NOT FOUND
C
C	MATCH ON '=' SIGN
C	SCAN BACKWARDS TO THE PRECEDING INDEX VARIABLE NAME
      IEQPOS = I
      DO 30 IBACK = 1,7
      IF (ISTR(IEQPOS-IBACK) .EQ. 0) GOTO 30 	! STILL PART OF NAME
      I = IEQPOS - IBACK		! POINT TO START OF NAME - 1
      GOTO 35
   30 CONTINUE
C
C	POSITIONED AT START OF VARIABLE NAME - 1.  PARSE NAME AND
C	STORE IN VAR
   35 J = 0
   40 I = I + 1
      IF (I .GT. IEND) RETURN
      IF (ISTR(I) .NE. 0) GOTO 50
      J=J+1				! J = NUMBER OF LETTERS OF NAME
      VAR(J)=STRING(I)
      GO TO 40
C
C	VARIABLE NAME NOW IN VAR, CALL CHECK TO DEFINE IT
50    IF (J.GT.0) CALL CHECK(J)
C	WRITE(6,6040) (VAR(II), II = 1,J)
C6040	FORMAT(' SUB WC: VAR =',6A1)
      IF (J.LT.0) RETURN
      GOTO 20			! CONTINUE PARSING REST OF EXPRESSION
      END