EWD number 
Size (KB) 
Title 

1200 
304 
Only a matter of style? 

1201 
89 
Triggered by Wim Feijen’s treatment of “Exists Forall ⇒ Forall Exists” 

1202 
83 
The complete (n + 1)graph in ndimensional space 

1203 
129 
Primes once more (re Kac & Ulam) 

1204 
100 
Complete DAGs 

1205 
124 
A trip to Harvard Law School, 10–11 April 1995 

1206 
81 
An unfortunate use of symbols 

1207 
37 
A theorem about “factors” perhaps worth recording 

1208 
200 
A result of rabbit removal 

1209 
174 
Why American Computing Science seems incurable 

1210 
134 
The nonunique node multiplicity 

1211a 
435 
On some very binary patterns (dedicated to F.E.J. Kruseman Aretz) 

1212 
114 
For the record: painting the squared plane 

1213 
149 
Introducing a course on calculi 

1214 
55 
The marriage agency 

1215 
131 
Courtesy Dr. Birgit Schieder 

1216 
39 
The equation x: [x] 

1217 
377 
Comments on a Review of the Department 

1218 
70 
A few addenda to EWD1192 

1219 
93 
“I have a proof that ....” 

1220 
29 
Honors course “Mathematical Methodology”, Spring 1996 

1221a 
115 
Points in the plane (unfinished) 

1221b 
235 
Calculational proof design; an experiment 

1222 
85 
Inspired by ~[x] equiv [~x] 

1223 
49 
WLOG, or the misery of the unordered pair 

1224 
98 
Hm++, a new Professional Standard (From the desk of the chairman of the Board of Mathematics Inc.) 

1225 
150 
Misra’s weakest fair buffer 

1226 
24 
A simple geometrical theorem I did not know 

1227 
109 
A somewhat open letter to David Gries 

1228 
71 
Sylvester’s theorem used (see EWD1016) 

1229 
139 
Nondeterministic construction of an arbitrary witness 

1230 
271 
Three very little problems from Eindhoven 

1231 
63 
The arithmetic and geometric means once more 

1232 
21 
My simplest theorem 

1233 
97 
A hint from monotonicity? 

1234 
82 
A problem communicated by Laurens de Vries 

1235 
87 
Een scheve schaats (English) 

1236 
113 
The wifeswapping couples once more (See EWD1103 and EWD1115) 

1237 
32 
Elegance and effective reasoning (Fall 1996) 

1238 
89 
Foreword 

1239 
556 
A first exploration of effective reasoning 

1240 
1767 
A little bit of lattice theory (replaced by 1240a) 

1240a 
638 
A little bit of lattice theory 

1241 
73 
The transitive closure of a wellfounded relation 

1243 
168 
The next fifty years 

1243a 
198 
The next fifty years 

1244 
36 
The formula for sin(alpha + beta) 

1244a 
32 
The formula for sin.(alpha + beta) 

1245 
81 
A kind of converse of Leibniz’s Principle 

1246 
44 
Courtesy Rajeev Joshi 

1247 
66 
Beware of the empty range 

1248 
46 
Homework #1 (See EWD996) 

1249 
65 
Andrew’s challenge once more (see EWD1247) 

1250 
67 
The couples, the river, and the little boat 

1251 
122 
Two problems derived from Hugo Steinhaus 

1252 
183 
Convocation speech, December 8, 1996 

1253 
23 
Mathematical induction’s fixpoint 

1254 
63 
A sequel to EWD1241 and WF 233/AvG 141 

1255 
296 
Pruning the search tree 

1256 
77 
Mathematical Methodology, Spring 1997 

1257 
76 
Defining the greatest common divisor 

1258 
45 
The ladder theorem 

1258a 
51 
The ladder theorem 

1260 
116 
The marked coins and the scale 

1261 
83 
The angle bisectors of a triangle 

1263 
26 
A correction to EWD1240 

1265 
56 
The theorem of de Ceva once more 

1266a 
130 
Proving an implication via its converse 

1267 
227 
On the determinant of the product of two square matrices 

1268 
319 
The Mathematical Divide 

1269 
118 
A simple proof of Hall’s Theorem 

1270 
113 
How closures could have been invented 

1271 
273 
N cheers for determinants (N>>0) 

1272 
92 
A Geometry Problem from “The Monthly”, March 1998 

1273 
79 
On Dijkstra’s Lemma and Kruskal’s Algorithm 

1274 
143 
For the record: Yossi Shiloach’s Algorithm 

1276 
262 
The algebraic core of a propositional logic (with Rutger M. Dijkstra) 

1277 
346 
Society’s role in mathematics 

1278 
255 
A calculational example 

1279 
77 
A simple country dance for transitivity and shunting 

1280 
270 
A tough experiment with the triangle calculus 

1280a 
350 
A formula is worth a thousand pictures (dedicated to Charles Antony Richard Hoare) 

1281 
98 
An iteration for the kth root with cubic convergence 

1282 
83 
On graphs whose nodes are Black or White 

1283 
70 
How “they” try to corrupt “us” 

1284 
727 
Computing Science: Achievements and Challenges 

1285 
202 
To Cambridge by mistake (13–18 April 1999) 

1286 
67 
A partition theorem of Euler’s generalized 

1287 
182 
Dear Tony, dearest Jill, and other people, dear or not 

1288 
68 
Ulrich Berger’s argument rephrased 

1289 
100 
A 2–colouring problem in the rational plane 

1290 
45 
Eliminating cascading carries 

1291 
110 
Courtesy Georg Cantor and Jayadev Misra 

1292 
67 
When a symmetric operator distributes over (up) and (down) 

1293 
200 
Constructing the Binary Search once more 

1294a 
179 
Designing a calculational proof of Cantor’s theorem 

1295 
144 
On the transitive closure of a wellfounded relation 

1296 
156 
On weighted means, geometric and arithmetic 

1296a 
96 
On weighted means, geometric and arithmetic 

1297 
84 
Triggered by a highschool exercise 

1298 
544 
Under the spell of Leibniz’s Dream 

1299 
52 
On defining sets, suprema, and infima 
