SUBROUTINE MATMULT(A1,A2,A3)
      implicit real*8 (a-h,o-z)
      include 'DIMENSIONS'
      DIMENSION A1(3,3),A2(3,3),A3(3,3)
      DIMENSION AI3(3,3)
      DO 1 I=1,3
        DO 2 J=1,3
          A3IJ=0.0
          DO 3 K=1,3
    3       A3IJ=A3IJ+A1(I,K)*A2(K,J)
          AI3(I,J)=A3IJ
    2   CONTINUE
    1 CONTINUE
      DO 4 I=1,3
      DO 4 J=1,3
    4   A3(I,J)=AI3(I,J)
      RETURN
      END