EWD number 
Size (KB) 
Title 

1100 
46 
The computing habit 

1101 
79 
Triangles in graphs: a sharp bound 

1102 
118 
Why preorders are beautiful 

1103 
37 
For the record: ETAC and the couples 

1104 
25 
So much for scientific visualization 

1105 
41 
For Bill Walker a sequel to EWD1099 

1106 
115 
Courtesy Apt, ETAC, Hoogerwoord, & Voermans 

1107 
462 
On extreme solutions 

1108 
80 
Too much PSST in Texas 

1109 
33 
Simplifying a proof in our book 

1110 
134 
To the members of the budget council (Confidential) 

1111 
144 
Triggered by Higman’s Lemma 

1112 
109 
Why “up to equivalence” 

1113 
107 
A somewhat open letter to Ben Kuipers 

1114 
157 
Wellfoundedness and the relational calculus 

1115 
250 
A manuscript for the Coahuila student chapter of the ACM 

1116 
106 
More pointless relational calculus: the transitive closure 

1117 
25 
Monotonic demonstranda and dummy introduction 

1118 
64 
On a formula designed by Henk Doornbos 

1119 
22 
A correction of EWD1112 

1120 
101 
Manipulating mathematical macros 

1121 
83 
Covering rectangles with bars of length 3 

1122 
78 
Interleaving is associative 

1123 
1085 
The unification of three calculi 

1124 
85 
On a proof of Kaplansky’s Theorem 

1125 
112 
A summary for Turner’s class (An extract from EWD1107) 

1126 
75 
Who failed? 

1127 
53 
Referee’s Report on "A transformational approach to specifying recovery in asynchronous communicating systems" by Zhiming Liu and Mathai Joseph, University of Warwick. Paper No. 40 (withdrawn) 

1128 
118 
Mathematical induction synthesized 

1129 
32 
Why “heavyweight” bits are unavoidable 

1130 
666 
On the economy of doing mathematics 

1131 
76 
Bulterman’s theorem on shortest tree 

1132 
56 
Introducing a course on the design and use of calculi 

1133 
83 
A theorem of Scholten’s once more (see EWD1048) 

1134 
110 
The checkers problem told to me by M.O. Rabin 

1135 
124 
The knight’s tour 

1136 
166 
A comparison of relational proofs 

1137 
103 
Computing the future? 

1138 
65 
Totalorder junctivity 

1139 
82 
A relational bagatelle 

1140 
75 
The arithmetic mean and the geometric mean 

1141 
236 
Notational considerations and the relational calculus 

1142 
42 
It is all distributivity 

1143 
200 
Some annotated proofs 

1144 
221 
More annotated proofs (a sequel to 1143) 

1145 
35 
A somewhat open letter to Cathleen Synge Morawetz 

1146 
65 
The transitivity of the implication 

1147 
101 
More on monotonic predicate transformers and the introduction of dummies (see EWD1117) 

1148 
76 
A more disentangled characterization of extreme solutions 

1149 
87 
Perry Moerland’s proof of Carel Scholten’s theorem 

1150 
589 
On the design of calculational proofs 

1151 
100 
A terrible Thursday 

1152 
148 
Het intellectuele gehalte van informatica 

1153 
145 
On bags and identical twins 

1154 
448 
A derivation of a proof by D. Zagier 

1155 
77 
A prime is in at most 1 way the sum of 2 squares 

1155a 
127 
A prime is in at most 1 way the sum of 2 squares 

1156 
61 
Voorwoord (voor jaarboek studievereniging UT) 

1157 
188 
Introducing a course on program design and presentation 

1158 
85 
A bagatelle on Euclid’s Algorithm 

1159 
112 
A note on “tail invariants” 

1160 
74 
How subtypes should enter the picture 

1161 
49 
How promiscuous are the French ? 

1162 
125 
A detailed derivation of a very simple program 

1163 
97 
Transitivity as an (unexpected?) consequence 

1164 
230 
A tentative axiomatization of ascending sequences 

1165 
276 
There is still a war going on 

1166 
295 
“From my Life” 

1167 
65 
A regrettable cover 

1168 
44 
On two equations that have the same extreme solution 

1169 
55 
An alternative of the ETAC to EWD1163 

1170 
92 
Equilateral triangles and rectangular grids 

1171 
137 
The argument about the arithmetic mean and the geometric mean, heuristics included 

1172 
108 
Pythagorean triples, or the design of a theorem 

1173 
106 
A theorem proved by John Segers 

1174 
176 
The heuristics of a proof by Jan L.A. van de Snepscheut and Richard S. Bird 

1174a 
202 
Heuristics for a calculational proof 

1175 
332 
The strengths of the academic enterprise 

1176 
111 
A chutzpah 

1177 
124 
In Memoriam Jan L.A. van de Snepscheut 

1178 
88 
On an argument by J.A. Carruth & J. Misra 

1179 
91 
A sorry parade 

1180 
103 
Heuristics for a very simple Euclidean proof 

1181 
32 
Don’t mix unary pre and postfix operators 

1182 
68 
Counting characters 

1183 
48 
“Less than” in terms of “at most” 

1184 
103 
Our book’s omission on quantification over scalar subtypes 

1185 
180 
Lifting, orders, and the Galois connection 

1186 
43 
Pingpong arguments and Leibniz’s principle 

1187 
155 
Boolean connectives yield punctual expressions 

1188 
115 
A problem from Zhendong Patrick Su (including an alternative solution by R.Boute 

1189 
38 
Another pingpong argument from Leibniz’s principle 

1190 
111 
Problem 10406 from The American Mathematical Monthly, Volume 101, Number 8 / October 1994 

1191 
83 
Junctivity and massaging quantification 

1192 
150 
The very first beginnings of lattice theory 

1193 
262 
On arcs and angles 

1194 
68 
Z.P. Su’s second problem 

1195 
84 
Another forced pingpong argument? 

1196 
79 
Generators of extreme values 

1197 
120 
A termination argument 

1198 
55 
Jan van de Snepscheut’s tiling problem 

1199 
63 
A supplement to EWD1140 and EWD1171 
