Sat 9 Dec 2023 : extended solution_drops for hexa double precision.

Thu 30 Nov 2023 : moved ts_ddsols.adb and ts_qdsols.adb into a new test
  package test_solutions_io, with extensions for other precisions.
  Removed ts_ddsols.adb and ts_qdsols.adb, new ts_sols_io.adb.
  Updated solutions.gpr.  New hexadobl_complex_solutions and _io,
  extended test_solutions_io.  The code of ts_solstr.adb was made
  into a new package test_solution_strings.  New ts_syssols_io,
  with tests defined by test_system_and_solutions_io, and
  hexadobl_system_and_solutions_io.  Updated solutions.gpr.

Tue 13 Jul 2021 : updated standard_system_and_solutions_io, so phc -z -p
  without output file writes directly to screen.

Fri 15 Jun 2021 : removed the obsolete mergesols.adb.

Thu 10 Jun 2021 : added the exec_dir attribute to solutions.gpr.

Wed 9 Jun 2021 : defined solutions.gpr to build the test procedures.

Mon 22 Feb 2021 : to standard_system_and_solutions_io added a main procedure.

Wed 17 Feb 2021 : moved the scan_for_start_system from ts_getstart
  to the package standard_system_and_solutions_io.
  Renamed drivers_for_solution_filters into main_solution_filters,
  moved code from ts_solfilt into test_solution_filters.
  Updated mainfilt.adb.  Moved mainfilt into main_solution_filters,
  removed the files mainfilt.ads and mainfilt.adb.

Tue 16 Feb 2021 : extended ts_getstart.adb with a procedure to read
  the start system and its solutions for an input file.

Mon 15 Feb 2021 : new test ts_getstart.adb to extract the start system
  and start solutions from the output file of the blackbox solver.

Sun 1 Nov 2020 : new test_dictionary_solutions and test_maple_solutions,
  packages with code from ts_dicsols_io and ts_mapsols_io.

Wed 23 Sep 2020 : extended solution_drops with operations on solutions in
  triple, penta, octo, and deca double precision.

Tue 22 Sep 2020 : added {trip,pent,octo,deca}dobl_complex_solutions, its _io,
  and {trip,pent,octo,deca}dobl_system_and_solutions_io. 

Thu 6 Aug 2020 : updated *_system_and_solutions_io.adb to output systems
  that have a different number of polynomials than equations.

Fri 10 Jul 2020 : in {standard,dobldobl,quaddobl}_system_and_solutions_io.adb
  made the dot dot dot consistent with other prompters.

Thu 11 Jun 2020 : updated drivers_for_condition_tables for the extra
  verbose level parameter.

Wed 10 Jun 2020 : new package standard_solutions_heap with code from the
  test procedure ts_newcirc.

Tue 9 Jun 2020 : generalized the get/put procedures in all
  *_system_and_solutions_io packages with a banner string option.

Mon 16 Mar 2020 : to {standard,dobldobl,quaddobl}_mixed_residuals, added
  functions to compute the mixed residuals directly from vectors.

Thu 2 Jan 2020 : for compiler warnings, modified ts_quad, ts_quadpart,
  standard_complex_solutions.adb, standard_complex_solutions_io.adb,
  standard_solution_array_lists.adb, ts_sols, ts_mapsols_io, ts_dicsols_io.

Sun 24 Mar 2019 : added functions and procedures to *mixed_residuals to
  evaluate the formulas for the mixed residuals directly, given evaluations.

Tue 12 Mar 2019 : removed superfluous documentation from the body of
  quaddobl_mixed_residuals.adb.

Sat 9 Mar 2019 : exposed the Write_Residuals function to the specification
  of the *_mixed_residuals packages.

Fri 8 Mar 2019 : completed adding output file types to the procedures
  and functions in standard_mixed_residuals.  Completed similar adds
  to the {dobldobl,quaddobl}_mixed_residuals, tested by ts_mixres.

Thu 7 Mar 2019 : added output to standard_mixed_residuals and ts_mixres.

Wed 6 Mar 2019 : extended standard_mixed_residuals for evaluable forms
  and copied into double double and quad double versions, with more tests
  in ts_mixres.

Tue 5 Mar 2019 : extended standard_mixed_residuals for Laurent polynomials
  and systems of polynomials, tested by ts_mixres.

Mon 4 Mar 2019 : basic version of computing a new residual in
  standard_mixed_residuals, tested by ts_mixres.

Sun 30 Dec 2018 : extended *_solution_filters* with functions to select the
  start solutions corresponding to failed paths, tested in ts_trasols_io.
  Updated ts_trasols_io, so the start system is written in front of the
  start solutions which correspond to failed paths.
  New package drivers_for_failed_paths, with code from ts_trasols_io and
  with drivers for use in phc -v, updated drivers_for_condition_tables.adb.

Sat 29 Dec 2018 : new procedure ts_trasols_io.adb to develop processing of
  the output file of a tracker.  Extended the code in ts_trasols_io and
  moved to new packages {standard,dobldobl,quaddobl}_tracked_solutions_io.

Fri 6 Apr 2018 : added a zero_singular_split_filter to the
  {standard,dobldobl,quaddobl}_solution_splitters, to remove the singular
  solutions from the solutions with nonzero slack variables.

Fri 30 Mar 2018 : in {standard,dobldobl,quaddobl}_solution_splitters,
  improved the interface to the singular filters.

Mon 9 Oct 2017 : new package standard_solution_manipulators to remove the
  imaginary part of the target.  Made dobldobl and quaddobl versions of
  this new package.

Fri 23 Jun 2017 : moved packages prompt_for_systems and prompt_for_solutions
  from the Main folder to the Solutions folder.

Fri 13 Jan 2017 : new package symbols_io with utilities factored out from
  standard_complex_solutions_io.adb.  Use symbols_io for double double and
  quad doubles in {dobldobl,quaddobl}_complex_solutions_io.adb.

Thu 12 Jan 2017 : in standard_complex_solutions_io.adb, added exception 
  handler in the get() procedure, so phc -b -v no longer crashes when there
  is a solution vector with NaN coordinates.  Fixed the skip_line(file)
  in standard_complex_solutions_io.adb, only skip if ch /= '='.

Mon 8 Aug 2016 : to standard_complex_solutions_io added a put_vector to
  work on vectors of complex numbers.  Did the same for the dobldobl and
  the quaddobl versions.

Tue 17 Nov 2015 : versions for double double and quad double precision of
  the solution_splitters, in {dobldobl, quaddobl}_solution_splitters.

Wed 7 Oct 2015 : fixed ts_grepsols.adb for code that was factored out of
  the drivers_for_condition_tables.

Tue 29 Sep 2015 : new packages {dobldobl,quaddobl}_solution_filters to filter
  solutions given in double double and quad double precision, with drivers in
  drivers_for_solution_filters, tested by ts_solfilt and called by mainfilt.

Mon 28 Sep 2015 : new packages {dobldobl,quaddobl}_point_lists,
  tested by ts_ptlists, and new packages {dobldobl,quaddobl}_quad_trees,
  tested by ts_quadpart.  Factored code of the drivers_for_condition_tables
  into standard_select_solutions, new packages *dobl_select_solutions,
  tested by ts_selsol.  This changes also mainfilt.adb, ts_quad.db.
  New packages *dobl_solution_diagnostics, *dobl_condition_{tables,report},
  called by drivers_for_condition_tables.

Thu 24 Sep 2015 : to {dobldobl,quaddobl}_complex_solutions, added a push
  procedure to insert a list of solutions to the front of another list.

Mon 29 Dec 2014 : extended standard_solution_strings with write functions
  to string for variable precision use.  Be careful with one variable case!

Thu 25 Dec 2014 : new package solution_string_splitters tested by ts_solstr.

Sun 7 Dec 2014 : new package varbprec_complex_solutions to convert solutions
  over various levels of precision.

Tue 26 Aug 2014 : extended {dobl,quad}dobl_complex_solutions_io with output
  routines for the diagnostics of a solution.

Fri 20 Jun 2014 : proper adjustment of multiplicity field in the procedure
  Multiplicity of standard_condition_report.

Thu 19 Jun 2014 : insert with duplicates in standard_point_lists is extended
  with extra parameter for the position of the added point.

Wed 18 Jun 2014 : added another insert to standard_point_lists for use
  in the Multiplicity of standard_condition_report.

Tue 17 Jun 2014 : added insert routines to standard_point_lists,
  tested with ts_ptlists.  Added more efficient Is_Clustered to
  the package standard_condition_report.

Thu 29 May 2014 : changed {standard,dobldobl,quaddobl,multprec}_complex_
  solutions_io.adb to remove all compiler warnings.

Wed 28 May 2014 : changed {standard,dobldobl,quaddobl,multprec}_complex_
  solutions_io.adb for compiler warnings.

Fri 29 Nov 2013 : changed copy of multprec_complex_solutions.adb 
  and fixed a bug in the copy of lists of multiprecision solutions,
  which occurred while upgrading ts_extrapol to multiprecision.

Thu 27 Jun 2013 : updated drivers_for_solution_filters.adb for a warning.

Wed 26 Jun 2013 : updated mainfilt.adb for natural32 data type.

Tue 25 Jun 2013 : standard_solution_splitters got updated with integer32.

Wed 12 Jun 2013 : updated {dobldobl,quaddobl}_systems_and_solutions_io.adb.

Mon 10 Jun 2013 : copied lists_of_symbols from ../Homotopy to here
  and completed reorganzation for all ts_ files.

Sun 9 Jun 2013 : about half of the files in this directory changed
  because of the introduction of natural32 and integer32 types.

Fri 10 May 2013 : new package standard_condition_report to avoid the
  confusion in drivers_for_condition_tables, tested by ts_quad.adb,
  also additions to standard_select_solutions.

Thu 9 May 2013 : copied from ../Homotopy the standard_point_lists.a*
  because there are needed by standard_quad_trees.
  Modified ts_selsol.adb to allow for interactive input of indices.
  New package standard_select_solutions, used in ts_quad.adb.
  Copied from ../Homotopy the mainfilt.a* and modified mainfilt.adb,
  because of changes in drivers_for_condition_tables.
  Also ts_grepsols.adb changed.

Fri 15 Feb 2013 : the parse operations in *_solution_strings* now
  initialize the symbol table.

Thu 14 Feb 2013 : new package solution_drops tested by ts_soldrop.

Fri 1 Feb 2013 : fixed bug in dobldobl_solution_strings.adb,
  the same bug appeared in quadobl_solution_strings.adb.

Tue 29 Jan 2013 : multprec_solution_strings.adb got fixed.
  New packages {dobldobl,quaddobl}_solution_strings, tested by ts_solstr.

Mon 28 Jan 2013 : changed standard_solution_strings.ads, new package
  multprec_solution_strings, tested by ts_solstr.adb.

Sun 20 Jan 2013 : created this new directory from code of Homotopy:
  all that concerns the representation of solutions.
