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| Burnaby: Burrard Inlet |
LANGER, SUSANNE K (1953)(1967) An Introduction to Symbolic Logic, Dover Publications, New York.
A review of the Langer text continued with a brief entry...
Philosopher Langer states that combined with 'nt' there are sixteen propositions. I would gather A nt A, B nt B, C nt C, D nt D are included (71). I put together the possible propositions A nt B, B nt A, etcetera and arrived at twelve, thankfully before seeing that Langer also had twelve. (77). She points out that the four all fail as not true. Something cannot be north of itself.
Cited
'To express the fact that a relation fails, i.e. that the proposition in which it functions is not true, it is customary to enclose the proposition in parentheses and prefix this whole expression by the sign ~. (72).
~ (A nt A) means fails. House 'A' is not north of house 'A'. (72).
Langer therefore presents...
A nt B
~(B nt A)
(73).
'The falsity of the latter follows from the truth of the former...' (73). The author points out that it is possible that neither is north of the other (same latitude north, my add), but both cannot be north of each other.
---
N (North Pole)
S (South Pole)
N nt S
~(S nt N)
My add.
In mathematics (the tilde) ~ means approximately or equivalence relation, in logic ~ means not, or as Langer presented, false/fails. I know from experience that some social research methods/statistical terms have slightly different meanings than in a philosophy context. I have mentioned on this website that while I was completing my PhD, I was working in both academic disciplines. This was particularly tricky in preparing for the PhD viva.
I can reason that ~ could be used rather often today, especially online...
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| Burnaby: Burrard Inlet |
