do *not* enforce scalable fonts for T1 encoding, instead rely on cm-super fonts, which also provide underscore for non-tt font;

--- a/src/Doc/IsarImplementation/document/root.tex	Sun Feb 09 16:17:01 2014 +0100
+++ b/src/Doc/IsarImplementation/document/root.tex	Sun Feb 09 16:31:24 2014 +0100
@@ -1,6 +1,5 @@
 \documentclass[12pt,a4paper,fleqn]{report}
 \usepackage[T1]{fontenc}
-\usepackage{ae}
 \usepackage{latexsym,graphicx}
 \usepackage[refpage]{nomencl}
 \usepackage{iman,extra,isar,proof}

--- a/src/Doc/IsarRef/document/root.tex	Sun Feb 09 16:17:01 2014 +0100
+++ b/src/Doc/IsarRef/document/root.tex	Sun Feb 09 16:31:24 2014 +0100
@@ -1,6 +1,5 @@
 \documentclass[12pt,a4paper,fleqn]{report}
 \usepackage[T1]{fontenc}
-\usepackage{ae}
 \usepackage{amssymb}
 \usepackage{eurosym}
 \usepackage[english]{babel}

--- a/src/Doc/System/document/root.tex	Sun Feb 09 16:17:01 2014 +0100
+++ b/src/Doc/System/document/root.tex	Sun Feb 09 16:31:24 2014 +0100
@@ -1,6 +1,5 @@
 \documentclass[12pt,a4paper]{report}
 \usepackage[T1]{fontenc}
-\usepackage{ae}
 \usepackage{supertabular}
 \usepackage{graphicx}
 \usepackage{iman,extra,isar,ttbox}