C***BEGIN PROLOGUE  CMPTR3
C***SUBSIDIARY
C***PURPOSE  Subsidiary to CMGNBN
C***LIBRARY   SLATEC
C***TYPE      COMPLEX (TRI3-S, CMPTR3-C)
C***AUTHOR  (UNKNOWN)
C***DESCRIPTION
C
C     Subroutine to solve tridiagonal systems.
C
C***SEE ALSO  CMGNBN
C***ROUTINES CALLED  (NONE)
C***REVISION HISTORY  (YYMMDD)
C   801001  DATE WRITTEN
C   890206  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900402  Added TYPE section.  (WRB)
C***END PROLOGUE  CMPTR3