Abstract of Chap. 8
The term "practical logic" means the logic in measurement theory. It is certain that pure logic (=mathematical logic) is merely a kind of rule in mathematics (or meta-mathematics). If it is so, the mathematical logic is not guaranteed to be applicable to our world. For instance, mathematical syllogism ( "$A \Rightarrow B$" and "$B \Rightarrow C$" imply "$A \Rightarrow C$" ) does not assure the following famous statement:
That is, we think that
$(\sharp_1):$ Since Socrates is a man and all men are mortal, it follows that Socrates is mortal.
In this chapter, we prove the $(\sharp_1)$ in classical systems. Also, we point out that syllogism does not hold
in quantum systems
This chapter is mostly extracted from
the following:
$(\sharp_2):$ the above ($\sharp_1 $) is not clarified yet.
[1]: S. Ishikawa, "Mathematical Foundations of Measurement Theory,"Keio University Press Inc. 2006.
( download free) [2]: S. Ishikawa, "Fuzzy Inferences by Algebraic Method," Fuzzy Sets and Systems, Vol. 87, No. 2, 1997, pp.181-200.doi: 10.1016/S0165-0114(96)00035-8
( download free)
Again recall that, as mentioned in $\S$1.1, the main purpose of this book is to
assert the following figure 1.1:
8.0: Practical logic - Do you believe in syllogism?
This web-site is the html version of "Linguistic Copehagen interpretation of quantum mechanics; Quantum language [Ver. 4]" (by Shiro Ishikawa; [home page] )
PDF download : KSTS/RR-18/002 (Research Report in Dept. Math, Keio Univ. 2018, 464 pages)