From bf2a7db4f8b033386b2a6288e852bf3992f70091 Mon Sep 17 00:00:00 2001
From: David Kaufmann <astra@ionic.at>
Date: Mon, 8 Apr 2019 03:44:34 +0200
Subject: [PATCH] more explanation

---
 ex1/main_5.tex | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ex1/main_5.tex b/ex1/main_5.tex
index 4779678..7e17f2b 100644
--- a/ex1/main_5.tex
+++ b/ex1/main_5.tex
@@ -170,7 +170,8 @@ Planning time: 3.295 ms
 Execution time: 3330.766 ms
 \end{verbatim}
 
-And move that semijoin for each post to a simple value comparison
+And move that semijoin for each post to a simple value comparison,
+because ``some $x$ exists where $f(x)$ is larger than $y$'' equals ``$y < max(f(x))$'',
 \begin{verbatim}
 SELECT p.*, c.*, u.* FROM posts p
 JOIN comments c ON p.id = c.postid
-- 
2.43.0