SUBROUTINE XDCSRT(DNU1,NUDIFF,MU1,MU2,THETA,P,Q,R,IP,IQ,IR,C1,IC1
     1   ,C2,IC2)
C***BEGIN PROLOGUE   XDCSRT
C***DATE WRITTEN   820728   (YYMMDD)
C***REVISION DATE  850805   (YYMMDD)
C***CATEGORY NO.  C3a2,C9
C***KEYWORDS  LEGENDRE FUNCTIONS
C***AUTHOR  SMITH, JOHN M. (NBS AND GEORGE MASON UNIVERSITY)
C***PURPOSE  TO COMPUTE CHECK VALUES FOR LEGENDRE FUNCTIONS
C***DESCRIPTION
C
C        SUBROUTINE XDCSRT CALCULATES CASORATI (CROSS PRODUCT)
C        CHECK VALUES AND STORES THEM IN ARRAYS C1 AND C2 WITH
C        EXPONENTS IN ARRAYS IC1 AND IC2.  CALCULATIONS ARE BASED
C        ON PREVIOUSLY CALCULATED LEGENDRE FUNCTIONS OF THE
C        FIRST KIND (NEGATIVE ORDER) IN ARRAY P, THE SECOND KIND
C        IN ARRAY Q, THE FIRST KIND (POSITIVE ORDER) IN ARRAY R.
C        RESULTS SHOULD BE 1.0 TO WITHIN ROUNDOFF ERROR.
C
C***REFERENCES  OLVER AND SMITH,J.COMPUT.PHYSICS,51(1983),N0.3,502-518.
C***ROUTINES CALLED  XDADD, XDADJ, XDRED
C***END PROLOGUE  XDCSRT