I spent a splendid week at Schloss Dagstuhl for Dagstuhl Seminar 14451: Optimality and tight results in parameterized complexity. As usual, this was intellectually extremely stimulating and very exhausting.

My head is full of tempting research ideas that I immediately need to pursue. Instead, I finalised a small cryptic crossword about parameterized complexity. If you are in the tiny demographic targeted by this puzzle, enjoy!

[As PDF]

Across
7 Freethinker Nelson hides a smaller problem. (6)
8 Mr No is crazy for graphs like K₅ and K_3,3. (6)
9 Remote application for algorithm rejected initially. (4)
10 Uppermost parts of perennial Unix command for displaying acyclic graph in PostScript? (8)
11 Peer pressured? (8)
13 Gadget for viewing booty in the mirror. (4)
14 Leaders of Japanese universities lament yearly when ICALP is. (4)
15 The German left room before Erik Demaine briefly blushed. (8)
16 Holger Dell, perhaps, to date teen in disguise. (8)
19 At the start of reduction, apply a trick. (4)
20 Rod is covered in soft hair, reportedly. (6)
21 Importance of mean and variance, for instance. (6)

Down
1 Important concept in exponential time complexity is belittling to slave. (4-9)
2 A connected, bridgeless cubic graph with chromatic index equal to 4 expresses “I love you” in a sharply critical fashion. (8)
3 Leaf lattice contains a set whose closure equals itself. (4)
4 Aunt had intercourse, as represented on a surface. (8)
5 Sounds like you mend one. (4)
6 Unix filesystem in important kernelization. (13)
12 Ask wordy drunk when Dagstuhl seminars take place. (8)
13 Robertson and Seymour’s results maybe confused me and others. (8)
17 Blow nose for very long running times. (4)
18 At first, Eppstein liked minimum spanning trees. (4)