# [Tex/LaTex] the capital Greek letter for tau?

greek

I would like to typeset the capital Greek letter for tau. I used \Tau, but I got error for that:

Undefined control sequence.

My preamble is

\documentclass[10pt,a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}


I was wondering what goes wrong?

since many of the greek uppercase letters have the same shape as latin letters, they were not separately provided for tex, for two reasons:

• to save space (which was a real consideration in 1980);

• because it wouldn't be possible to tell the difference between the two shapes.

the first reason is no longer relevant, of course, but the second is.

\newcommand{\Tau}{\mathrm{T}}

\def\Tau{{\rm T}}