\documentclass[12pt]{article}
\usepackage{amstext}
\usepackage[greek]{babel}
\usepackage[iso-8859-7]{inputenc}
\begin{document}
{\large
$\mathbf{\text{\textrm{ì}}{\displaystyle\prod}\text{\textrm{ë}}\forall}$
}
\end{document}
