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Single Idea 9540

[filed under theme 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL ]

Full Idea

A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0.

Gist of Idea

A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0

Source

GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)

Book Ref

Hughes,G./Cresswell,M.: 'An Introduction to Modal Logic' [Methuen 1972], p.10

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A Reaction

In the interpreted version of the logic, 1 and 0 would become T (true) and F (false). The procedure seems to be called nowadays a 'valuation'.

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The 4 ideas from GE Hughes/M Cresswell

9540	A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]

9541	The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]

9543	The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]

9544	A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]