\\makeatletter
\\newif \\if@frontmatter   \\@frontmatterfalse
\\let \\LaTeXfrontmatter = \\frontmatter
\\let \\LaTeXmainmatter  = \\mainmatter
\\renewcommand {\\frontmatter} {\\@frontmattertrue  \\LaTeXfrontmatter}
\\renewcommand {\\mainmatter}  {\\@frontmatterfalse \\LaTeXmainmatter}

\\pagestyle{fancy}
  \\fancyhf{}
  \\fancyhead[RE]{\\if@frontmatter\\else\\small \\CAST@value@titlemark\\fi}
  \\fancyhead[LO]{\\if@frontmatter\\else\\small \\leftmark\\fi}
  \\fancyhead[LE,RO]{\\if@frontmatter\\else\\small ~\\thepage~\\fi}
  \\fancyfoot[C]{\\if@frontmatter\\small ~\\thepage~\\fi}
  \\renewcommand{\\headrulewidth}{\\if@frontmatter 0pt\\else .7pt\\fi}%
\\fancypagestyle{plain}{%
  \\pagestyle{fancy}
}
\\makeatother