closely to the tops of the
original pages. These may be searched for to locate the material
referred to. In the main section, these page markers are always given
with 3 digits including, if necessary, leading zeroes.

This book contains a large number of line drawn illustrations which are
un-credited. As these cannot be rendered here in the original manner
they have been reproduced as well as possible in the manner known as
"ASCII art".


A number of transcription errors were found in the original book. As
these were clearly not part of the Author's intention they have, as far
as possible, been identified and corrected in accordance with the
methods given by the Author. These corrections are listed here below
with their locations and original text. In these notes the word
'natural' identifies a letter symbol occurring without a prime mark.

Page viii: "189" corrected to "194".
Page viii: "188" corrected to "192".
Page xv, '=Real=' and '=Unreal=', or '=Imaginary=', Classes: "1Ѕ"
          corrected to "2".
Page xix, Propositions beginning with "Some": "18" corrected to "19".
Page xix, Rules: "19" corrected to "20".
Page xix, The West and East Halves ...: "24" corrected to "23".
Page xxi, The Proposition "All x are y" ...: was originally shown as
          occurring in page 34.
Page xxii, And of three other similar arrangements: "37" corrected to
          "36".
Page xxiii, The Proposition 'No xm exist': "43" corrected to "44".
Page 060: "contruct" corrected to "construct".
Page 094, Paper V: missing word "it" supplied.
Page 111, #28: "No h are k-natural" corrected to "No h are k-prime".
Page 111, #30: "No a are h-natural" corrected to "No a are h-prime".
Page 111, #30: "No c are n-natural" corrected to "No c are n-prime".
Page 123, #57 (d): "mortally offended if I fail to notice them"
          corrected to "mortally offended".
Page 128, #34: "Some x-prime are y" corrected to "Some x-natural are y".
Page 146, #30: "x_{1}m-prime_{0}" corrected to "x_{1}m-natural_{0}".
Page 147, #32: "xm-natural_{0}" corrected to "xm-prime_{0}".
Page 156, #18 (4/1): "be" corrected to "be-sub:zero".
Page 156, #22 (5/1): "ch" corrected to "ch-sub:zero".
Page 157, #23 (5/2): second underline corrected from single to double.
Page 157, #23 (2/2): first underline corrected from single to double.
Page 157, #23 (¶2): "h_{1}c" corrected to "h_{1}c-sub:zero".
Page 157, #26 (5/1): "a_{1}c-natural_{0}" corrected to
          "a_{1}c-prime_{0}".
Page 157, #26 (¶2): "e_{1}c-natural_{0}" corrected to
          "e_{1}c-prime_{0}".
Page 157, #29 (8/2): first underline corrected from single to double.
Page 161, #36 (4/2): "e'd-prime" corrected to "e'd-natural".
Page 161, #39 (1/2): "c-prime+d" corrected to "c-natural+d".
Page 161, #40: "a" and "b" interchanged.
Page 161, #43 (1/1): "b-natural_{1}e_{0}" corrected to
          "b-prime_{1}e_{0}".
Page 162, #52 (3/1): "h'k-prime_{0}" corrected to "h'k-natural_{0}".
Page 163, #55 (3/2): "c'd-prime" corrected to "c'd-natural".
Page 163, #57 (1/2): "h-natural+d'" corrected to "h-prime+d'".


In the original book at the top of page 97, the following text occurred:

    [N.B. The numbers at the foot of each page indicate the pages
    where the corresponding matter may be found.]

In accordance with the un-paged medium here this has been changed to:

    [N.B. Reference tags for Examples, Answers & Solutions will be
    found in the right margin.]

The part of the book to which this relates contains, by sections,
"Examples" (Exercises for the student), "Answers" (to the Examples) &
"Solutions" (Worked Answers). All Example sections have corresponding
Answer sections. For Sections 2 & 3, worked Solutions are not supplied;
for Sections 4-7, Solutions are given by 2 different methods. In
association with this, the original text contained editorial notes at
the foot of each page giving the page numbers for the related Sections.
In this version, these notes are replaced with marginal tags such as
EX3, AN4, SL5, & SL6-A and SL7-B which are placed at the top of each
Section to identify the current location. As with page tags, these may
be searched for to locate the material refered to. (A search for "SL4"
should find successively both "SL4-A" & "SL4-B".) These tags are unique
regardless of case.