C
C     ..................................................................
C
C        SUBROUTINE DQL12
C
C        PURPOSE
C           TO COMPUTE INTEGRAL(EXP(-X)*FCT(X), SUMMED OVER X
C                               FROM 0 TO INFINITY).
C
C        USAGE
C           CALL DQL12 (FCT,Y)
C           PARAMETER FCT REQUIRES AN EXTERNAL STATEMENT
C
C        DESCRIPTION OF PARAMETERS
C           FCT    - THE NAME OF AN EXTERNAL DOUBLE PRECISION FUNCTION
C                    SUBPROGRAM USED.
C           Y      - THE RESULTING DOUBLE PRECISION INTEGRAL VALUE.
C
C        REMARKS
C           NONE
C
C        SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
C           THE EXTERNAL DOUBLE PRECISION FUNCTION SUBPROGRAM FCT(X)
C           MUST BE FURNISHED BY THE USER.
C
C        METHOD
C           EVALUATION IS DONE BY MEANS OF 12-POINT GAUSSIAN-LAGUERRE
C           QUADRATURE FORMULA, WHICH INTEGRATES EXACTLY,
C           WHENEVER FCT(X) IS A POLYNOMIAL UP TO DEGREE 23.
C           FOR REFERENCE, SEE
C           SHAO/CHEN/FRANK, TABLES OF ZEROS AND GAUSSIAN WEIGHTS OF
C           CERTAIN ASSOCIATED LAGUERRE POLYNOMIALS AND THE RELATED
C           GENERALIZED HERMITE POLYNOMIALS, IBM TECHNICAL REPORT
C           TR00.1100 (MARCH 1964), PP.24-25.
C
C     ..................................................................
C
      SUBROUTINE DQL12(FCT,Y)
C
C
      DOUBLE PRECISION X,Y,FCT
C
      X=.37099121044466920D2
      Y=.8148077467426242D-15*FCT(X)
      X=.28487967250984000D2
      Y=Y+.30616016350350208D-11*FCT(X)
      X=.22151090379397006D2
      Y=Y+.13423910305150041D-8*FCT(X)
      X=.17116855187462256D2
      Y=Y+.16684938765409103D-6*FCT(X)
      X=.13006054993306348D2
      Y=Y+.8365055856819799D-5*FCT(X)
      X=.9621316842456867D1
      Y=Y+.20323159266299939D-3*FCT(X)
      X=.68445254531151773D1
      Y=Y+.26639735418653159D-2*FCT(X)
      X=.45992276394183485D1
      Y=Y+.20102381154634097D-1*FCT(X)
      X=.28337513377435072D1
      Y=Y+.9044922221168093D-1*FCT(X)
      X=.15126102697764188D1
      Y=Y+.24408201131987756D0*FCT(X)
      X=.61175748451513067D0
      Y=Y+.37775927587313798D0*FCT(X)
      X=.11572211735802068D0
      Y=Y+.26473137105544319D0*FCT(X)
      RETURN
      END