C #LOGTRI V1A 15-FEB-72. C LAST UPDATE: C LOGICAL FUNCTION LOGTRI(J1,J2,J3) C C *PURPOSE. C TO TEST THE TRIANGLE RELATIONS FOR ANGULAR MOMENTUM C QUANTUM NUMBERS J1, J2, AND J3. THAT IS DETERMINE IF THEY C CAN COUPLE TO ZERO ANGULAR MOMENTUM. C C *PARAMETERS: C C J1 - THE FIRST ANGULAR MOMENTUM QUANTUM NUMBER C J2 - THE SECOND C J3 - THE THIRD C C NOTE!! BY CONVENTION ALL QUANTUM NUMBERS ARE INTEGERS WITH C TWICE THEIR PHYSICAL VALUE. C C INPUT PARAMETERS: C J1, J2, J3 C OUTPUT PARAMETERS: C ( THE LOGICAL FUNCTION VALUE ) C C *METHOD. C STRAIGHTFORWARD. THE LOGICAL VALUE ".TRUE." IS RETURNED C IF THE REALTIONS ARE SATISFIED ELSE ".FALSE." C C *ACCURACY. C C *RESTRICTIONS. C C *ERROR CONDITIONS. C C *NON STANDARD ROUTINES CALLED. C PARITY - RETURNS + OR -1 AS ARG EVEN OR ODD - MRMLIB C C *TYPICAL TIMES. C C *ORIGIN. M.R.MANNING. C C *COMMENTS. C C #END. C LOGTRI=.FALSE. IF(J1) 100,11,11 11 IF(J2) 100,12,12 12 IF(J3) 100,13,13 13 K=J1+J2+J3 IF(PARITY(K)) 100,15,15 15 IF (K - 2*MAX0(J1, J2, J3) ) 100,16,16 16 LOGTRI= .TRUE. C 100 RETURN END