Lewis Carroll - Crocodile Story

From Sylvie & Bruno Vol's I & II (Page 101 [227 of the first ed. and 121 in this PDF])

“And one day—when we was in Outland, oo know—before we came to Fairyland—me and Sylvie took him a big Crocodile. And he shortened it up for us. And it did look soo [228] funny! And it kept looking round, and saying ‘wherever is the rest of me got to?’ And then its eyes looked unhappy—” 

“Not both its eyes,” Sylvie interrupted.

“Course not!” said the little fellow. “Only the eye that couldn’t see wherever the rest of it had got to. But the eye that could see wherever—” ...

The reason I looked at this is that I was thinking about the real closed field and fractal crocodiles and farey sequences, ...

Original (animated!) Image of F(1), F(2), F(3), F(5), F(7) and F(9). Note that F(9) includes F(3) as a subsequence.

 See Paul Halmos' book Measure Theory:

The pre-requisites § 0 includes Heine–Borel theorem for which you are further required to understand what it means for a set to be closed and bounded, and what is a cover of a set, and what is a finite subcover. But that's probably OK, as in the Preface he states "The beginner should be warned that some of the words and symbols in the latter part of § 0 are defined only later, in the first seven chapters of the text, and that, accordingly, he should not be discouraged if, on first reading of § 0, he finds that he does not have the prerequisites for reading the prerequisites." This seems to be a joke about Lebesgue measure. Perhaps Halmos is the origin of it? Chapter XII is "Measure and Topology in Groups".