SUBROUTINE LDOVAR COMMON /LISTDO/ LPT, LEN, LS(64) C C CHECKS PROPER NESTING OF DOS WITHIN LIST CONSTRUCT C IF (LPT.GE.61) GO TO 50 DO 40 KQ=LPT,60,4 KK = KQ + 4 DO 30 L=1,4 LL = L + KQ - 1 IF (LS(LL)) 10, 30, 10 10 DO 20 K=KK,61,4 IF (LS(K).EQ.LS(LL)) CALL ERROR1( *57H ILLEGAL TO CHANGE VALUE OF CONTROL VARIABLE OR DO LIMITS, 57) 20 CONTINUE 30 CONTINUE 40 CONTINUE 50 RETURN END