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Single Idea 9719
[filed under theme 5. Theory of Logic / K. Features of Logics / 3. Soundness
]
Full Idea
If every proof-theoretically valid inference is semantically valid (so that |- entails |=), the proof theory is said to be 'sound'.
Gist of Idea
A proof theory is 'sound' if its valid inferences entail semantic validity
Source
Herbert B. Enderton (A Mathematical Introduction to Logic (2nd) [2001], 1.1.7)
Book Ref
Enderton,Herbert B.: 'A Mathematical Introduction to Logic' [Academic Press 2001], p.2
The
12 ideas
with the same theme
[whether all formal deductions always lead to truth]:
19123
|
If soundness can't be proved internally, 'reflection principles' can be added to assert soundness
[Gödel, by Halbach/Leigh]
|
9719
|
A proof theory is 'sound' if its valid inferences entail semantic validity
[Enderton]
|
10765
|
Soundness would seem to be an essential requirement of a proof procedure
[Tharp]
|
10070
|
If everything that a theory proves is true, then it is 'sound'
[Smith,P]
|
10086
|
Soundness is true axioms and a truth-preserving proof system
[Smith,P]
|
10596
|
A theory is 'sound' iff every theorem is true (usually from true axioms and truth-preservation)
[Smith,P]
|
13635
|
'Weakly sound' if every theorem is a logical truth; 'sound' if every deduction is a semantic consequence
[Shapiro]
|
10120
|
Soundness is a semantic property, unlike the purely syntactic property of consistency
[George/Velleman]
|
18757
|
Soundness theorems are uninformative, because they rely on soundness in their proofs
[McGee]
|
16342
|
You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system
[Halbach]
|
16341
|
Normally we only endorse a theory if we believe it to be sound
[Halbach]
|
16344
|
Soundness must involve truth; the soundness of PA certainly needs it
[Halbach]
|