proper \usepackage[T1]{fontenc};

--- a/src/HOL/Bali/document/root.tex	Wed Mar 10 19:03:24 2021 +0100
+++ b/src/HOL/Bali/document/root.tex	Wed Mar 10 20:09:26 2021 +0100
@@ -1,5 +1,5 @@
-
 \documentclass[11pt,a4paper]{book}
+\usepackage[T1]{fontenc}
 \usepackage{isabelle,isabellesym}
 \usepackage{latexsym}
 \usepackage{graphicx}

--- a/src/HOL/Hoare/document/root.tex	Wed Mar 10 19:03:24 2021 +0100
+++ b/src/HOL/Hoare/document/root.tex	Wed Mar 10 20:09:26 2021 +0100
@@ -1,4 +1,5 @@
 \documentclass[11pt,a4paper]{article}
+\usepackage[T1]{fontenc}
 \usepackage{graphicx}
 \usepackage[english]{babel}
 \usepackage{isabelle,isabellesym}

--- a/src/HOL/Proofs/Lambda/document/root.tex	Wed Mar 10 19:03:24 2021 +0100
+++ b/src/HOL/Proofs/Lambda/document/root.tex	Wed Mar 10 20:09:26 2021 +0100
@@ -1,4 +1,5 @@
 \documentclass[11pt,a4paper]{article}
+\usepackage[T1]{fontenc}
 \usepackage{graphicx}
 \usepackage[english]{babel}
 \usepackage{amssymb}