Combining Texts
Ideas for
'Politics', 'Intermediate Logic' and 'On Second-Order Logic'
expand these ideas
|
start again
|
choose
another area for these texts
display all the ideas for this combination of texts
7 ideas
5. Theory of Logic / K. Features of Logics / 2. Consistency
13540
|
A set of formulae is 'inconsistent' when there is no interpretation which can make them all true [Bostock]
|
13541
|
For 'negation-consistent', there is never |-(S)φ and |-(S)¬φ [Bostock]
|
13542
|
A proof-system is 'absolutely consistent' iff we don't have |-(S)φ for every formula [Bostock]
|
5. Theory of Logic / K. Features of Logics / 4. Completeness
10834
|
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
|
5. Theory of Logic / K. Features of Logics / 6. Compactness
13841
|
Why should compactness be definitive of logic? [Boolos, by Hacking]
|
13544
|
Inconsistency or entailment just from functors and quantifiers is finitely based, if compact [Bostock]
|
13618
|
Compactness means an infinity of sequents on the left will add nothing new [Bostock]
|