<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def com_google_fonts_check_version_bump(ttFont, api_gfonts_ttFont, github_gfonts_ttFont):
 """Version number has increased since previous release on Google Fonts?"""

  v_number = ttFont["head"].fontRevision
  api_gfonts_v_number = api_gfonts_ttFont["head"].fontRevision
  github_gfonts_v_number = github_gfonts_ttFont["head"].fontRevision
  failed = False

  if v_number == api_gfonts_v_number:
    failed = True
    yield FAIL, ("Version number {} is equal to"
                 " version on Google Fonts.").format(v_number)

  if v_number < api_gfonts_v_number:
    failed = True
    yield FAIL, ("Version number {} is less than"
                 " version on Google Fonts ({})."
                 "").format(v_number,
                            api_gfonts_v_number)

  if v_number == github_gfonts_v_number:
    failed = True
    yield FAIL, ("Version number {} is equal to"
                 " version on Google Fonts GitHub repo."
                 "").format(v_number)

  if v_number < github_gfonts_v_number:
    failed = True
    yield FAIL, ("Version number {} is less than"
                 " version on Google Fonts GitHub repo ({})."
                 "").format(v_number,
                            github_gfonts_v_number)

  if not failed:
    yield PASS, ("Version number {} is greater than"
                 " version on Google Fonts GitHub ({})"
                 " and production servers ({})."
                 "").format(v_number,
                            github_gfonts_v_number,
                            api_gfonts_v_number)