Rule of Material Implication/Definition
Jump to navigation
Jump to search
Theorem
The Rule of Material Implication can be used as a definition for the logical operator that is implication:
- $p \implies q := \neg p \lor q$
Historical Note
The Rule of Material Implication as a definition appears in the introductory material of 1910: Alfred North Whitehead and Bertrand Russell: Principia Mathematica: Volume $\text { 1 }$, and some other authors follow their lead.
Sources
- 1910: Alfred North Whitehead and Bertrand Russell: Principia Mathematica: Volume $\text { 1 }$ ... (previous) ... (next): Chapter $\text{I}$: Preliminary Explanations of Ideas and Notations