example of quantifier
there are some examples and theorems about logical quantifiers
in the Word Document below .you can download it:
http://www.freewebs.com/hkkass
or
http://www.hkkass.blogspot.com/
I include extracts of this Document below:
Definition: a property is something like or in which is a variable in some set. Such a formula is shown by , ,etc. if x is fixed then is a proposition
, i.e. it is a true or a false sentence
.
Example 1: let be the property where x is a real number. is true and is false.
Example 2: a property can have two or more variables. Let be . in this case is true but is false because is not equal to .
Definition: let be a property on the set , i.e. is a property and varies in the set .a) The symbol means for every in the set the proposition is true.b) The symbol means there is some in the set for which the proposition is true.If , i.e. if the set is empty, is defined to be true and is defined to be false.
Example 1: is a true proposition.
Example 2: is false, because no real number satisfies .
Example 3: is a property. varies in . As a result is a proposition, i.e. it is a true or a false sentence. In fact is false but is true; here is the interval containing real numbers greater than .
some theorems:
for proofs of the following theorems see the address above
Theorem 1: if and then .
Theorem 2: suppose is a singleton, i.e. a set with only one element. We have”” is equivalent to .
Theorem 22: if then .
here is a property on .