TeX-modeTeX-mode is an alias for `tex-mode' in `
tex-mode.el'. (TeX-mode) Major mode for editing files of input for TeX, LaTeX, or SliTeX. Tries to determine (by looking at the beginning of the file) whether this file is for plain TeX, LaTeX, or SliTeX and calls `plain-tex-mode', `latex-mode', or `slitex-mode', respectively. If it cannot be determined, such as if there are no commands in the file, the value of `tex-default-mode' says which mode to use.