d
e
Chapter 1
Logic and Sets
1.1. Logical connectives
1.1.1. Unambiguous statements. Logic is concerned first of all with
the logical structure of statements, and with the construction of complex
statements from simple parts. A statement is a declarative
Definitions, Axioms, Postulates, Propositions, and Theorems from Euclidean and
Non-Euclidean Geometries by Marvin Jay Greenberg (2009-03-26)
Logic Rule 0 No unstated assumptions may be used in a proof.
Logic Rule 1 Allowable justifications.
1. By hypothes
Definitions, Axioms, Postulates, Propositions, and Theorems from Euclidean and
Non-Euclidean Geometries, 4th Ed by Marvin Jay Greenberg (Revised: 18 Feb 2011)
Logic Rule 0 No unstated assumptions may be used in a proof.
Logic Rule 1 Allowable justificatio
MATH 4510/5510: Brown
Definitions-1
Selected Modern Definitions1
Definition. Two lines l and m are perpendicular if they intersect at a point B such that there is a ray
BA that is a part of l, a ray BC that is part of m, and ABC is a right angle.
Definiti