# HG changeset patch
# User Eugen Sawin <sawine@me73.com>
# Date 1335392700 -7200
# Node ID 175252b48ca16aa16585398f3fba27b13ff266c9
# Parent  3095afa54bea2cb3c6b4ba3a218aaee1bbad9ace
Added sol 1.2.

diff -r 3095afa54bea -r 175252b48ca1 exercises/solutions/sol01.tex
--- a/exercises/solutions/sol01.tex	Wed Apr 25 17:30:37 2012 +0200
+++ b/exercises/solutions/sol01.tex	Thu Apr 26 00:25:00 2012 +0200
@@ -1,4 +1,4 @@
-\documentclass[a4paper, 10pt, pagesize, smallheadings]{article}  
+\documentclass[a4paper, 10pt, pagesize, smallheadings]{article}
 \usepackage{graphicx}
 %\usepackage[latin1]{inputenc}
 \usepackage{amsmath, amsthm, amssymb}
@@ -18,7 +18,7 @@
 \begin{document}
 \maketitle
 
-\section*{Exercise 1.1a}
+\section*{Exercise 1.1}
 \begin{tabular}{|c|c|c||c|c|c||c|c|c|}
   \hline
   5&3&6 &4&7&2 &8&1&9 \\ \hline
@@ -32,5 +32,20 @@
   3&1&8 &2&4&5 &7&9&6 \\ \hline
   9&4&7 &3&6&1 &2&8&5 \\ \hline
   6&5&2 &7&8&9 &3&4&1 \\ \hline
-\end{tabular}
+\end{tabular} \\\\
+I have applied following strategies to solve the puzzle:
+\begin{itemize}
+  \item look for most contrained blocks, rows and columns
+  \item look for values with most resolved positions
+  \item annotate cells with consistent values
+  \item look for inconsistent connections between cell annotations
+\end{itemize}
+
+\section*{Exercise 1.2}
+(a) $R_{x,y} \bowtie S_{y,z} = \{(a,b,a),(a,b,c)\}$\\
+(b) $\sigma_{z=c}(R_{x,y} \bowtie S_{y,z}) = \{(a,b,c)\}$\\
+(c) $\pi_x(R_{x,y}) = \{(a)\}$\\
+(d) $R_{x,y} \circ S_{y,z} = \{(b,b)\}$\\
+
+
 \end{document}