An essay on the foundations of geometry · Bertrand Russell
TRANSCRIBER'S NOTE
Italic text is denoted by _underscores_. Bold text is denoted by =equal signs=. A superscript is denoted by ^{x}. For example, y^{4} indicates y to the power 4. A subscript is denoted by {x}. For example, a{ik} indicates the ik-th element of array a. Algebraic expressions in the original text usually had the variables in italic. The italic underscore markup has been removed for readability, so for example: _dx_{i}_ = λ′_d_′_x_{i}_ + λ″_d″x_{i}_ has been changed to: dx{i} = λ′d′x{i} + λ″d″x{i} Obvious typographical errors and punctuation errors have been corrected after careful comparison with other occurrences within the text and consultation of external sources. Except for those changes noted below, all misspellings in the text, and inconsistent or archaic usage, have been retained. For example, co-exist, coexist; every-day, everyday; connexion; assertorial; apodeictic; premisses. § 82, 'so Erdmannn confidently' replaced by 'so Erdmann confidently'. § 150 Footnote [157], 'Delboeuf' replaced by 'Delbœuf' for consistency. § 152, 'one subdivison must' replaced by 'one sub-division must'. § 159 Footnote [167], 'Delboeuf' replaced by 'Delbœuf' for consistency. § 204, 'and homogenous;' replaced by 'and homogeneous;'.
Text from Project Gutenberg, public domain in the United States.