--- a/ChengsongTanPhdThesis/Chapters/Chapter1.tex	Sat May 28 17:17:18 2022 +0100
+++ b/ChengsongTanPhdThesis/Chapters/Chapter1.tex	Mon May 30 14:41:09 2022 +0100
@@ -65,6 +65,9 @@
 \def\rup{r^\uparrow}
 %\def\bderssimp{\mathit{bders}\_\mathit{simp}}
 \def\distinctWith{\textit{distinctWith}}
+\def\lf{\textit{lf}}
+\def\PD{\textit{PD}}
+
 
 \def\size{\mathit{size}}
 \def\rexp{\mathbf{rexp}}