      SUBROUTINE PIMIX (BN,BNF,T,TX)
      IMPLICIT  REAL*8   (A-H,O-Z)
C *** SEE R H LANDAU, PROGRAM LPOTT, 1981
      DIMENSION BN(16), BNF(16), T(14), TX(14)
C     FORM PARTIAL WAVE DECOMP OF PI+P,PI+N AMPLIT UDES
C     -NON-FLIP, SP,SP,PP,PN,...
C     CODE FOR BN, BNF, BNUC, BNUCF
C     ALL FOR PI PLUS, REAARANGE FOR PI MINUS LATTER
C     1 RES,P 2 IMSP    3 RES,N        4 IMSN
C     5 REP,P 6IMP,P    7 REP,N        8 IMP,N
C     9 RED,P 10IMD,P   11 RED,N       12 IMD,N
C     13 REF,P          14 IMF,P       15 REF,N  16 IMF,N
C     17 REG,P          18 IMG,P       19 REG,N  20 IMG,N
      RHL = 2./3.
      BN(1) = T(1)
      BN(2) = TX(1)
      BN(3) = BN(1)/3.+RHL*T(4)
      BN(4) = BN(2)/3.+RHL*TX(4)
      BN(5) = T(2)+2.*T(3)
      BN(6) = TX(2)+2.*TX(3)
      BN(7) = BN(5)/3.+RHL*(T(5)+2.*T(6))
      BN(8) = BN(6)/3.+RHL*(TX(5)+2.*TX(6))
      BN(9) = 2.*T(7)+3.*T(8)
      BN(10) = 2.*TX(7)+3.*TX(8)
      BN(11) = BN(9)/3.+RHL*(2.*T(11)+3.*T(12))
      BN(12) = BN(10)/3.+RHL*(2.*TX(11)+3.*TX(12))
      BN(13) = 3.*T(9)+4.*T(10)
      BN(14) = 3.*TX(9)+4.*TX(10)
      BN(15) = BN(13)/3.+RHL*(3.*T(13)+4.*T(14))
      BN(16) = BN(14)/3.+RHL*(3.*TX(13)+4.*TX(14))
C     SPON FLIP,SAME ORDER AS ABOVE
      BNF(1) = 0.
      BNF(2) = 0.
      BNF(3) = 0.
      BNF(4) = 0.
      BNF(5) = T(3)-T(2)
      BNF(6) = TX(3)-TX(2)
      BNF(7) = BNF(5)/3.+RHL*(T(6)-T(5))
      BNF(8) = BNF(6)/3.+RHL*(TX(6)-TX(5))
      BNF(9) = T(8)-T(7)
      BNF(10) = TX(8)-TX(7)
      BNF(11) = BNF(9)/3.+RHL*(T(12)-T(11))
      BNF(12) = BNF(10)/3.+RHL*(TX(12)-TX(11))
      BNF(13) = T(10)-T(9)
      BNF(14) = TX(10)-TX(9)
      BNF(15) = BNF(13)/3.+RHL*(T(14)-T(13))
      BNF(16) = BNF(14)/3.+RHL*(TX(14)-TX(13))
      RETURN
      END
